Skip to main content
NCBI home page
ACS AuthorChoice logoLink to ACS AuthorChoice
. 2024 Oct 9;16(42):57870–57877. doi: 10.1021/acsami.4c12938

Interface Stability and Reaction Mechanisms of Li3YCl5Br with High-Voltage Cathodes and Li Metal Anode: Insights from Ab Initio Simulations

Andrey Golov †, Jian Xiang Lian †, Javier Carrasco †,‡,*
PMCID: PMC11503608  PMID: 39383334

Abstract

graphic file with name am4c12938_0010.jpg

Recent advancements in battery technology emphasize the critical role of solid electrolytes in enhancing the performance and safety of next-generation batteries. In this study, we investigate the interface stability and reaction mechanisms of Li3YCl5Br, a promising halide-based solid electrolyte, in contact with high-voltage Ni–Mn–Co (NMC) cathodes and a Li metal anode using ab initio molecular dynamics simulations. Our findings reveal that Li3YCl5Br reacts with charged NMC cathodes. This reaction involves changes in the oxidation states of Br– anions in Li3YCl5Br and d-element cations in NMC, as well as the diffusion of Li ions from the solid electrolyte to the cathode to maintain charge balance. The reaction is confined to the interface, suggesting bulk stability. Conversely, the Li/Li3YCl5Br interface exhibits significant instability, with a chemical reaction that results in substantial structural changes and the formation of LiCl and LiBr at the solid electrolyte surface and metallic Y at the Li anode surface. These insights provide valuable information for optimizing interfacial design, aiming at improving the performance and reliability of all-solid-state batteries using halide solid electrolytes.

Keywords: solid-state batteries, halide solid electrolytes, interface reactivity, battery interface modeling, ab initio molecular dynamics simulations

Introduction

Cutting-edge developments in battery technology have underscored the important role of solid electrolytes (SEs) in enhancing the safety, energy density, and overall performance of post-lithium-ion batteries (LIBs).1−5 In this quest, halide SEs6,7 have garnered significant attention due to their high room-temperature ionic conductivity,8,9 air/humidity durability,10,11 and excellent (electro)chemical stability with high-voltage cathode materials,12 all of which are crucial attributes for next-generation battery technologies.4

Among various candidates, SEs based on lithium yttrium chloride (Li3YCl6, LYC) have emerged as promising contenders due to their relatively high ionic conductivity, good deformability, and oxidative stability.13 In practice, doping LYC with aliovalent metals or substituting halogens are effective strategies to tune the properties of this class of SEs. For example, introducing trace amounts of fluorine into LYC has been found to enhance its oxidation stability without compromising ionic conductivity, thereby improving the charge–discharge efficiency of cathodes in solid-state batteries.14 Additionally, van der Maas et al. reported that substituting part of the Cl ions with Br can significantly increase the ionic conductivity in LYC.15 However, the introduction of Br may reduce high-voltage stability, leading to a trade-off between cathode compatibility and ionic conductivity. This is because bromides have a smaller electrochemical stability window compared to chlorides.8,16 Nevertheless, van der Maas et al. have shown that a small Br content does not affect the oxidative stability of the SE, yet it substantially increases ionic conductivity compared to pristine LYC.

Understanding the structure–property relationship of LYC is fundamental for designing high-performance SEs for advanced energy storage applications.17 However, to fully realize their potential in practical applications, it is crucial to go beyond a mere assessment of bulk properties and address the interfacial challenges associated with the formation of the solid electrolyte interface (SEI) in the Li metal anode18−20 and high-voltage cathodes.21,22 Recent studies indicate that halide SEs are particularly well suited for high-voltage cathodes due to their relatively high oxidation potential and chemical stability.8,12,23 However,8,12 the chemical decomposition of halide SEs on the Li metal anode and the mechanical instability associated with volume changes in Li metal can lead to instability at the anode–SE interface.18 Therefore, a thorough understanding of the reaction mechanisms, composition, and structure occurring at the interfaces is crucial for overcoming these challenges and assisting in the design of new materials.

In this context, this study investigates the interface stability of Li3YCl5Br (LYCB) SE in contact with high-voltage Ni–Mn–Co (NMC) cathodes and a Li metal anode. Using ab initio molecular dynamics (AIMD) simulations and a series of interface models, we delve into the dynamic evolution of these systems, providing valuable insights into electrolyte stability, reaction mechanisms, and intermediate products during the initial stages of interphase formation. Furthermore, we evaluate the impact of interfacial reactivity on Li-ion conductivity. Our findings aim to pave the way for optimizing halide-based SEs, ultimately enhancing the performance and reliability of next-generation battery technologies.

Methods

Density Functional Theory (DFT) Calculations

DFT calculations were performed using the Vienna ab initio simulation package (VASP) 5.4 code.24−26 The Perdew–Burke–Ernzerhof (PBE) exchange–correlation functional27 was employed along with PBE-based projector augmented wave potentials.28,29 The energy cutoff was set to 600 eV. For the bulk structures of the electrolyte, a Monkhorst–Pack Brillouin zone sampling30 with Γ-centered 1 × 1 × 2 k-point meshes was applied, while a Γ-only k-point mesh was used for the interface models. Geometry optimization was performed with a force convergence criterion of 0.05 eV/Å. To account for the strong on-site Coulomb interaction (U) in the relaxation of NMC/Li3YCl5Br interface models, the PBE + U approach31,32 with spin polarization was used. The U values were set to 5.14 eV for Co, 4.84 eV for Mn, and 5.96 eV for Ni.33 AIMD simulations were performed in the NVT ensemble at 298 K, with a time step of 1 fs, using a Nosé–Hoover thermostat34 with a Nosé mass parameter of 0.5. Bader atomic charges were calculated using the Bader code.35

Exploring the Configuration Space of the Solid Electrolyte

The solid electrolyte structural model was constructed based on the crystallographic data of Li3YCl4.8Br1.2 (Table S1). This compound crystallizes in the P3̅m1 space group, with unit cell parameters a = b = 11.372 Å and c = 6.169 Å, forming a hexagonal close-packed arrangement of anions.

The Supercell program36 was used to enumerate all possible symmetrically unique variants of Li-vacancies, Y-vacancies, and Cl–Br distributions within the LYCB structures. To avoid a combinatorial explosion, the site occupancies of the experimentally determined structure were adjusted to create manageable simulation supercells (Table S1); this adjustment resulted in a slight difference in composition between the modeled structure (Li3YCl5Br) and the actual experimental one (Li3YCl4.8Br1.2). A total of 1620 unique configurations of the SE were generated, and the configuration with the lowest energy was chosen to construct the interface models.

Interface Models

To study the stability of LYCB in contact with a cathode active material (AM) and a Li metal anode, we carried out AIMD simulations of the AM/LYCB and Li/LYCB interface models. These models were constructed using a lattice mismatch algorithm.37 The process involves two key steps: cleaving slabs along specific Miller planes from bulk structures and embedding these slabs into a single cell with a translation symmetry compatible with the slabs. The model construction was guided by two criteria: a maximum lattice vector length mismatch of 0.03 Å and a maximum angular mismatch of 0.01 radians. Additionally, the geometry of the models was relaxed before the subsequent AIMD simulation, and to minimize computational complexity by reducing the number of atoms within the interface model, we restricted the maximal surface area across the interface (a × b unit cell parameters) to 500 Å2. Larger sizes would result in prohibitive computational costs.

For simulating reactivity at the cathode side, we considered two Ni-rich NMC cathode materials, i.e., LiNi0.6Mn0.2Co0.2O2 (NMC622) and LiNi0.8Mn0.1Co0.1O2 (NMC811). We built three NMC622(001)/Li3YCl5Br(001) and three NMC811(001)/Li3YCl5Br(001) interface models, each with various Li-vacancy distributions within the cathode slab (Figure 1). The inclusion of various Li-vacancy distributions was necessary to introduce diversity in the structures, allowing us to examine different possibilities within a statistically relevant sample yet without generating an unmanageable number of configurations. Moreover, the Li-vacancy distributions were chosen to ensure a uniform charge distribution across the (001) NMC slab, resulting in slabs with a negligible dipole moment compared with other orientations, such as the (100) plane, where the breaking of metal–oxygen bonds leads to a pronounced separation of positive and negative charges on opposite sides of the slab. The (001) orientation was chosen to satisfy the criteria for the maximal surface area, making the AIMD calculations more feasible. Although this orientation may not be the most favorable for Li diffusion through the interface, it still enables the assessment of interface stability and reaction mechanisms.

Figure 1.

Figure 1

Open in a new tab

Initial NMC/Li3YCl5Br electrolyte interface structures considered in this study.

Given that the primary driving force of the chemical reaction between AM and SE is the electrochemical potential difference, we used the structures of the charged cathodes. Based on the experimental capacities of 175 mAh/g for NMC62238 and 200 mAh/g for NMC811,39 the Li fraction in one formula unit of the charged cathodes is approximately 0.37 and 0.28, respectively. The bulk cathode structures were constructed from a 4 × 4 × 1 supercell of LiCoO2 (mp-22526) obtained from the Materials Project database,40 which involved randomly removing some Li atoms and replacing some Co atoms with Mn and Ni. The SE structure used for the interface models is the lowest energy configuration obtained from the exploration of the configuration space.

Simulations of the anode side were performed for two Li/SE interface models constructed from the two lowest energy configurations of Li3YCl5Br and the Li metal structure (mp-51) from the Materials Project database (Figure 2). Detailed information about the interface models is shown in Table S2.

Figure 2.

Figure 2

Open in a new tab

Initial Li anode/Li3YCl5Br interface structures considered in this study.

Assessment of Li-Ion Diffusion

The Li-ion migration map and migration barriers of the interface models were calculated using the topological analysis of procrystal electron densities (TAPED) approach41,42 implemented in the IonExplorer2 program.43 The final frames of the AIMD trajectories served as the input configurations.

In contrast to the AIMD and DFT-based nudge elastic band method,44,45 the TAPED approach requires much less computational time that allows for the analysis of interface models and large supercells containing thousands of symmetrically nonequivalent ion migration pathways.46 Although TAPED calculates barrier values in electron density units, these values are linearly correlated with the actual barrier values obtained from the NEB method.42 This allows for the use of TAPED results in comparing relative barrier heights.

Results and Discussion

LYCB at Contact with the NMC Cathode

The geometry optimization of the NMC622(001)/Li3YCl5Br(001) and NMC811(001)/Li3YCl5Br(001) models results in significant changes in the coordination of some Y atoms at the interface (Figure S1). Specifically, this process involves the coordination of Y atoms with the O atoms from the NMC slab. Concurrently, some Y–Cl(Br) bonds break, and new Li–Cl(Br) contacts form. Similar structural changes were observed in previous DFT simulations of the LiCoO2/Li3YCl6 interface.47 A subsequent 20 ps long AIMD simulation reveals no further significant changes in the Y environments (Figure 3), with the total energy of the system monotonically decreasing within the first 5–10 ps of the simulation and then reaching a plateau (Figure S2).

Figure 3.

Figure 3

Open in a new tab

Final frames of the AIMD simulations for the NMC/Li3YCl5Br interface models.

To further investigate the possibility of redox reactions, a Bader charge analysis was conducted, revealing no significant charge transfer from the SE to the cathode. The average atomic charges remain constant throughout the simulations (Figure 4), indicating the absence of redox reactions at the AM/SE interfaces within the 20 ps simulation time frame. However, the distribution of individual atomic charges of halogens within the specific III.NMC811(001)/Li3YCl5Br(001) model reveals the presence of oxidized species (Figure S3).

Figure 4.

Figure 4

Open in a new tab

Evolution of average atomic charges throughout AIMD simulations of the NMC/Li3YCl5Br interface models. The lines connecting the data points serve as a visual guide.

To further analyze this intriguing result, we focus on the geometry optimization of this model, which indicates the oxidation of Br– ions, evidenced by a slightly positive atomic charge of approximately 0.18 electrons. The oxidizing agent in this case is clearly the NMC. The reaction proceeds via the mechanism depicted in Figure 5. At the solid electrolyte interface, Y coordinates with the atoms of the NMC cathode, breaking some Y–Cl and Y–Br bonds and forming new Li–Cl and O–Br contacts. Interestingly, comparable changes occur in the atomic environment of Y across the other models, except for the formation of the O–Br contacts. Consequently, the redox reaction appears to require coordination of the halogen atom with O of NMC. It is likely that the electron transfer from the halogen ion of the SE to the d-element cation of the NMC proceeds through the bridging oxygen. According to this mechanism, the reaction front should propagate solely along the interface, leaving the bulk of the SE and the cathode structure unaffected. This may result in the formation of a stable interface between the halide SE and the NMC cathode. Consequently, the amount of electrolyte degradation is determined by the interface surface area.

Figure 5.

Figure 5

Open in a new tab

Mechanism of the redox reactions observed during simulation of the III.NMC811(001)/Li3YCl5Br model. The fragments shown are taken from the initial model, the relaxed model, the 15 ps AIMD frame, and the 20 ps frame.

Further AIMD simulations of the III.NMC811(001)/Li3YCl5Br(001) model did not affect the charge distribution of the Br atoms. However, changes in the Cl charge (Figure S3) indicate the formation of another intermediate product. Specifically, at 15 ps of the AIMD simulation, oxidized Br coordinates with a near Cl ion, forming a bromine monochloride molecule (Figure 5). This reactive compound can potentially oxidize Br– ions, leading to the formation of Br2 and Cl–. Thus, Br2 formation can be expected among the reaction products with BrCl and Cl2 as intermediate products.

The reaction involves changes in oxidation states of Br– in the SE (Br– - e– → 1/2 Br20) and d-element cations of the NMC (Me4+ + e– → Me3+, where Me = Ni, Mn, and Co). Determining which d-element underwent reduction is challenging due to fluctuations in their Bader atomic charges. However, experimental data suggests that Ni is typically the first to be reduced.21

Maintaining the charge balance during the reaction requires the transfer of Li+ ions from the SE to the NMC. This transfer is indeed observed during geometry optimization and AIMD simulation. In the final frames of the AIMD trajectories, some of the Li ions initially belonging to the SE occupy vacant Li sites in the NMC at the interface region (Figure 3). Overall, the proposed general reaction equation is

graphic file with name am4c12938_m001.jpg

where 0.28 ≤ y < 1 and 0 < x < 1 – y.

The formation of reaction intermediates during geometry optimization of the III.NMC811(001)/Li3YCl5Br(001) model suggests a low activation energy. However, the optimization and subsequent AIMD simulation of the other investigated interface models did not indicate any redox reactions. This is evident from the distribution of individual atomic charges of Cl and Br ions (Figure S3) and the comparison of the NMC net charge of the interface models (Figure S4). Among all interface models, the III.NMC811(001)/Li3YCl5Br(001) model has the lowest net charge of the NMC slab. Although there is some fluctuation of the Br charge in the I.NMC811(001)/Li3YCl5Br(001) model (Figure S3), it does not lead to any redox activity.

Arguably, 20 ps AIMD simulations of relatively small interface models may not yield sufficiently comprehensive statistical data. Increasing the unit cell size and extending the simulation time could help us observe more reaction events. Nevertheless, the results reported here provide valuable insights into the interface stability and reaction mechanism, aligning well with the experimental data. In particular, a previous study on the thermal stability of charged NMC cathodes showed that the interaction between the NMC and Li3MCl6 (M = In, Y, Zr) SE mitigates oxygen release from the NMC via oxidative decomposition of the halide SE, accompanied by Cl2 gas release.21 The study found that the reaction proceeds via the reduction of Ni in the NMC by Cl– ions from the SE, along with the intercalation of Li from the SE into the cathode. Overall, the interface showed low reactivity within the temperature range of 40–130 °C, with negligible release of Cl2 gas. However, between 130 and 250 °C, notable electrolyte decomposition was observed, while the NMC structure remained relatively stable without severe structural changes. These findings support the reaction mechanism proposed in our study.

Now, we turn to the investigation of Li-ion mobility near the interfaces. The AIMD simulations of the AM/SE interface models reveal Li-ion diffusion between the SE and NMC, primarily confined to the interface region (Figures S1 and S3). This is evident by changes in the Li sites at the initial and final trajectory frames. No significant Li-ion diffusion is detected through the metal oxide layers of the cathode. However, Li ions exhibit a higher mobility in directions parallel to these layers. This suggests that while interlayer diffusion is limited, there is a notable tendency for Li-ion migration along the plane of the cathode metal oxide layers. This aligns well with a prior study of Li-ion diffusion in a layered LiCoO2 cathode.48

To better quantify this observation, we employed TAPED analysis (Figures 6 and S4) to find that migration barriers at the interface are comparable to those within the bulk SE. This indicates that Li ions can diffuse effectively along the (001)/(001) interface plane without significant resistance. However, Li-ion diffusion through the (001)/(001) interface is hindered by large migration barriers across the (001) NMC planes, which are higher by about 1 order of magnitude. This is primarily due to limited interatomic spacing. For Li ions to diffuse in the [001] direction, they must pass through narrow channels within the MO2 (M = Ni, Mn, Co) layers. In contrast, diffusion between cathode metal oxide layers encounters much less spatial constraint. The most favorable pathways for Li-ion migration within the cathode region align along (001) planes, forming a 2-periodic (repeats periodically in two directions) migration map. The results are consistent across all the investigated interface models (Figure S5). While our study focuses on the (001) orientation, it is clear that investigating models where the NMC layers are perpendicular to the interface could offer more favorable conditions for Li-ion migration.

Figure 6.

Figure 6

Open in a new tab

Final frame of the AIMD simulation of the NMC811(001)/Li3YCl5Br(001) interface model (left). Li-migration paths (middle) and the corresponding density profile (right). Blue and red colors indicate paths with low and high barriers, respectively. Insets: highlights of representative low- (green) and high-barrier (dark red) migration pathways.

Halide Solid Electrolyte Interface at Contact with the Li Metal Anode

The AIMD simulation of the Li(110)/Li3YCl5Br models reveals a chemical reaction between the electrolyte and the Li anode. In the final trajectory frames, notable changes in the Y coordination structures are observed (Figure 7). Specifically, the average coordination numbers of Y–Cl(Br) decrease, while the Li–Cl(Br) coordination numbers increase (Figure 8). Additionally, there is a Li-ion exchange between the metal and SE slab. However, the main diffusion gradient is directed from the Li slab toward the interface, likely caused by the chemical reaction. In the final AIMD frames, the interphase region contains a substantial number of reacted Li atoms from the metal slab (see Figure 7), while only a few Li from the electrolyte have migrated into the anode region. Throughout the entire simulation, the total potential energy decreases monotonically, which suggests the formation of low-energy reaction products (Figure S6).

Figure 7.

Figure 7

Open in a new tab

Final frames of the AIMD simulations of the Li anode/Li3YCl5Br interface models.

Figure 8.

Figure 8

Open in a new tab

Evolution of average coordination numbers throughout the AIMD simulations of the Li anode/Li3YCl5Br interface models.

According to Bader charge analysis, the reaction proceeds through the reduction of Y atoms by the Li metal anode. This is evidenced by the decreasing average atomic charges of Y and the increasing charges of Li within the anode slab (Figure 9). As expected, the charges of the anions remain constant. While there are some fluctuations in the charges of Li ions within the electrolyte, they are not related to redox reactions. Based on these findings, we can conclude that the Li anode reacts with the halide SE, resulting in the formation of the interphase products, Y, LiCl, and LiBr, according to the following reaction equation: Li3YCl5Br + 3Li → 5LiCl + LiBr + Y. In fact, when considering such bulk phase reaction and utilizing the structures of Li metal, LiCl, LiBr, and Y metal obtained from the Materials Project (mp-51, mp-22905, mp-23259, and mp-112, respectively, available at https://next-gen.materialsproject.org), the calculated reaction energy is exothermic, with a value of −1.83 eV per formula unit. These results are in good agreement with previous experimental and theoretical studies of similar halide SE.49−51 Interestingly, that reduced Y concentrated at the metal Li slab (Figure 7). A similar effect was observed in our previous study of the Li/Li3YCl4.25Br1.75 interface.50 Additionally, Ren et al.51 reported a comparable Y concentration in their AIMD simulation of the Li/Li3YCl6 interface, attributing this to the reduction and dissolution of Y3+ in the Li anode. However, we found no experimental data supporting the existence of Li–Y binary compounds. Moreover, the phase diagram generated from the Materials Project indicates that no thermodynamically stable Y–Li compounds exist. Perhaps the observed concentration of reduced Y at the Li slab may be due to the grain boundaries effect.

Figure 9.

Figure 9

Open in a new tab

Evolution of average atomic charges throughout AIMD simulations of the Li anode/Li3YCl5Br interface models. The lines serve as a visual guide.

A possible way to enhance halide solid electrolytes compatibility with Li metal anode is to use a protective coating. For instance, Li3N demonstrates high ionic conductivity and forms a stable interface with Li anode.52 Similarly, LiCl and Li3P coatings are expected to stabilize the interface by minimizing Li dendrite growth and preventing electrolyte degradation.52 Looking forward, the next step could be to simulate Li/coating/LYCB interfaces to assess the impact of coatings on interfacial properties.

Conclusions

We investigated the dynamic evolution of the Li3YCl5Br SE in contact with NMC622 and NMC811 cathodes as well as a Li metal anode using AIMD simulations. The simulations reveal that Li3YCl5Br undergoes a reactive interaction with the charged NMC cathodes. The proposed reaction equation is

graphic file with name am4c12938_m002.jpg

This reaction involves the oxidation of Br– in the SE (Br– - e– → 1/2 Br2) and the reduction of d-element cations in the NMC (Me+4 + e– → Me+3). To maintain charge balance, Li ions diffuse from the SE to the NMC. The reaction mechanism includes the coordination of Y with O from the NMC at the interface, leading to the breaking of the Y–Cl and Y–Br bonds and the formation of Br–O–Me contacts. Notably, electron transfer from Br– to Me4+ appears to occur via bridging oxygen. The identified intermediate reaction products include B and BrCl species. Since the reaction is confined only to the interface without affecting the bulk of the SE or cathode structure, the NMC/Li3YCl5Br interface is expected to be stable. Furthermore, TAPED indicates that Li-ion diffusion through the NMC(001)/Li3YCl5Br(001) interface is hindered by high ion migration barriers. However, the Li-ion migration barriers along the interface are comparable to those in the bulk electrolyte.

In contrast, the Li/Li3YCl5Br interface exhibits strong instability. AIMD simulations reveal a significant chemical reaction between Li and Li3YCl5Br, resulting in significant structural changes of the SE. The reaction propagates from the interface into the bulk electrolyte, with the possible reaction equation being:

graphic file with name am4c12938_m003.jpg

This reaction is associated with a reduced concentration of metal Y at the Li metal anode surface.

The insights from this study enhance our understanding of reaction mechanisms at halide SE interfaces with NMC cathodes and Li anodes. These findings are relevant for optimizing interface design and, thereby, improving the performance and stability of all-solid-state batteries based on halide SEs.

Acknowledgments

This work has received funding from the European Union’s Horizon Europe programme for research and innovation under grant agreement no. 101069681 (HELENA Project). The authors gratefully acknowledge the technical support provided by the Barcelona Supercomputing Center and the computer resources from SCAYLE and CENITS (QHS-2023-3-0007, QHS-2024-1-0004), SGI/IZO-SGIker UPV/EHU, and i2BASQUE academic network. Additionally, The authors thank Saint-Gobain Ceramics for providing the crystallographic data of Li3YCl4.8Br1.2.

Supporting Information Available

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsami.4c12938.

  • Additional characteristics of the interface models and computational details (PDF)

The authors declare no competing financial interest.

Supplementary Material

am4c12938_si_001.pdf (1.5MB, pdf)

References

  1. Chen C.; Jiang M.; Zhou T.; Raijmakers L.; Vezhlev E.; Wu B.; Schülli T. U.; Danilov D. L.; Wei Y.; Eichel R. A.; Notten P. H. L. Interface Aspects in All-Solid-State Li-Based Batteries Reviewed. Adv. Energy Mater. 2021, 11 (13), 2003939 10.1002/aenm.202003939. [DOI] [Google Scholar]
  2. Banerjee A.; Wang X.; Fang C.; Wu E. A.; Meng Y. S. Interfaces and Interphases in All-Solid-State Batteries with Inorganic Solid Electrolytes. Chem. Rev. 2020, 120 (14), 6878–6933. 10.1021/acs.chemrev.0c00101. [DOI] [PubMed] [Google Scholar]
  3. Tan D. H. S.; Banerjee A.; Chen Z.; Meng Y. S. From Nanoscale Interface Characterization to Sustainable Energy Storage Using All-Solid-State Batteries. Nat. Nanotechnol. 2020, 15 (3), 170–180. 10.1038/s41565-020-0657-x. [DOI] [PubMed] [Google Scholar]
  4. Janek J.; Zeier W. G. Challenges in Speeding up Solid-State Battery Development. Nat. Energy 2023, 8 (3), 230–240. 10.1038/s41560-023-01208-9. [DOI] [Google Scholar]
  5. Tarascon J. M.; Armand M. Issues and Challenges Facing Rechargeable Lithium Batteries. Nature 2001, 414 (6861), 359–367. 10.1038/35104644. [DOI] [PubMed] [Google Scholar]
  6. Kwak H.; Wang S.; Park J.; Liu Y.; Kim K. T.; Choi Y.; Mo Y.; Jung Y. S. Emerging Halide Superionic Conductors for All-Solid-State Batteries: Design, Synthesis, and Practical Applications. ACS Energy Lett. 2022, 7 (5), 1776–1805. 10.1021/acsenergylett.2c00438. [DOI] [Google Scholar]
  7. Li X.; Liang J.; Yang X.; Adair K. R.; Wang C.; Zhao F.; Sun X. Progress and Perspectives on Halide Lithium Conductors for All-Solid-State Lithium Batteries. Energy Environ. Sci. 2020, 13 (5), 1429–1461. 10.1039/C9EE03828K. [DOI] [Google Scholar]
  8. Kim K.; Park D.; Jung H. G.; Chung K. Y.; Shim J. H.; Wood B. C.; Yu S. Material Design Strategy for Halide Solid Electrolytes Li3MX6(X = Cl, Br, and I) for All-Solid-State High-Voltage Li-Ion Batteries. Chem. Mater. 2021, 33 (10), 3669–3677. 10.1021/acs.chemmater.1c00555. [DOI] [Google Scholar]
  9. Kwak H.; Han D.; Lyoo J.; Park J.; Jung S. H.; Han Y.; Kwon G.; Kim H.; Hong S. T.; Nam K. W.; Jung Y. S. New Cost-Effective Halide Solid Electrolytes for All-Solid-State Batteries: Mechanochemically Prepared Fe3+-Substituted Li2ZrCl6. Adv. Energy Mater. 2021, 11 (12), 2003190 10.1002/aenm.202003190. [DOI] [Google Scholar]
  10. Wang K.; Ren Q.; Gu Z.; Duan C.; Wang J.; Zhu F.; Fu Y.; Hao J.; Zhu J.; He L.; Wang C. W.; Lu Y.; Ma J.; Ma C. A Cost-Effective and Humidity-Tolerant Chloride Solid Electrolyte for Lithium Batteries. Nat. Commun. 2021, 12 (1), 4410 10.1038/s41467-021-24697-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Li X.; Liang J.; Luo J.; Norouzi Banis M.; Wang C.; Li W.; Deng S.; Yu C.; Zhao F.; Hu Y.; Sham T. K.; Zhang L.; Zhao S.; Lu S.; Huang H.; Li R.; Adair K. R.; Sun X. Air-Stable Li3InCl6 Electrolyte with High Voltage Compatibility for All-Solid-State Batteries. Energy Environ. Sci. 2019, 12 (9), 2665. 10.1039/C9EE02311A. [DOI] [Google Scholar]
  12. Asano T.; Sakai A.; Ouchi S.; Sakaida M.; Miyazaki A.; Hasegawa S. Solid Halide Electrolytes with High Lithium-Ion Conductivity for Application in 4 V Class Bulk-Type All-Solid-State Batteries. Adv. Mater. 2018, 30 (44), 1803075 10.1002/adma.201803075. [DOI] [PubMed] [Google Scholar]
  13. Ito H.; Nakahira Y.; Ishimatsu N.; Goto Y.; Yamashita A.; Mizuguchi Y.; Moriyoshi C.; Toyao T.; Shimizu K. I.; Oike H.; Enoki M.; Rosero-Navarro N. C.; Miura A.; Tadanaga K. Stability and Metastability of Li3YCl6 and Li3HoCl6. Bull. Chem. Soc. Jpn. 2023, 69 (11), 1262. 10.1246/bcsj.20230132. [DOI] [Google Scholar]
  14. Yamagishi M.; Zhong C.; Shibata D.; Morimoto M.; Orikasa Y. Effect of Fluorine Substitution in Li3YCl6 Chloride Solid Electrolytes for All-Solid-State Battery. Electrochemistry 2023, 91 (3), 037002 10.5796/electrochemistry.23-00005. [DOI] [Google Scholar]
  15. van der Maas E.; Zhao W.; Cheng Z.; Famprikis T.; Thijs M.; Parnell S. R.; Ganapathy S.; Wagemaker M. Investigation of Structure, Ionic Conductivity, and Electrochemical Stability of Halogen Substitution in Solid-State Ion Conductor Li3YBrxCl6–x. J. Phys. Chem. C 2023, 127 (1), 125–132. 10.1021/acs.jpcc.2c07910. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Wang S.; Bai Q.; Nolan A. M.; Liu Y.; Gong S.; Sun Q.; Mo Y. Lithium Chlorides and Bromides as Promising Solid-State Chemistries for Fast Ion Conductors with Good Electrochemical Stability. Angew. Chem., Int. Ed. 2019, 58 (24), 8039. 10.1002/anie.201901938. [DOI] [PubMed] [Google Scholar]
  17. Liu Z.; Chien A.; Wang S.; Lin Z.; Liu J.; Mo Y.; Chen H.. Insights into the Crystal Structure of Halide Solid Electrolytes and Li Diffusion ECS Meeting Abstracts 2022; Vol. MA2022–02 (4), 10.1149/ma2022-024390mtgabs. [DOI]
  18. Guo L.; Zheng J.; Zhao L.; Yao Y. Interfacial Instabilities in Halide-Based Solid-State Batteries. MRS Bull. 2023, 48, 1247–1256. 10.1557/s43577-023-00607-3. [DOI] [Google Scholar]
  19. Yun J.; Shin H. R.; Hoang T. D.; Kim S.; Choi J. H.; Kim B.; Jung H.; Moon J.; Lee J. W. Deciphering the Critical Degradation Factors of Solid Composite Electrodes with Halide Electrolytes: Interfacial Reaction versus Ionic Transport. Energy Storage Mater. 2023, 59, 102787 10.1016/j.ensm.2023.102787. [DOI] [Google Scholar]
  20. Tao B.; Zhong D.; Li H.; Wang G.; Chang H. Halide Solid-State Electrolytes for All-Solid-State Batteries: Structural Design, Synthesis, Environmental Stability, Interface Optimization and Challenges. Chem. Sci. 2023, 14 (33), 8693–8722. 10.1039/D3SC02093B. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Lee S.; Kim Y.; Park C.; Kim J.; Kim J. S.; Jo H.; Lee C. J.; Choi S.; Seo D. H.; Jung S. K. Interplay of Cathode-Halide Solid Electrolyte in Enhancing Thermal Stability of Charged Cathode Material in All-Solid-State Batteries. ACS Energy Lett. 2024, 9 (4), 1369–1380. 10.1021/acsenergylett.4c00033. [DOI] [Google Scholar]
  22. Kochetkov I.; Zuo T. T.; Ruess R.; Singh B.; Zhou L.; Kaup K.; Janek J.; Nazar L. Different Interfacial Reactivity of Lithium Metal Chloride Electrolytes with High Voltage Cathodes Determines Solid-State Battery Performance. Energy Environ. Sci. 2022, 15 (9), 3933–3944. 10.1039/D2EE00803C. [DOI] [Google Scholar]
  23. Liu Y.; Wang S.; Nolan A. M.; Ling C.; Mo Y. Tailoring the Cation Lattice for Chloride Lithium-Ion Conductors. Adv. Energy Mater. 2020, 10 (40), 2002356 10.1002/aenm.202002356. [DOI] [Google Scholar]
  24. Kresse G.; Hafner J. Ab Initio Molecular Dynamics for Liquid Metals. Phys. Rev. B 1993, 47 (1), 558–561. 10.1103/PhysRevB.47.558. [DOI] [PubMed] [Google Scholar]
  25. Kresse G.; Furthmüller J. Efficiency of Ab-Initio Total Energy Calculations for Metals and Semiconductors Using a Plane-Wave Basis Set. Comput. Mater. Sci. 1996, 6 (1), 15–50. 10.1016/0927-0256(96)00008-0. [DOI] [Google Scholar]
  26. Kresse G.; Furthmüller J. Efficient Iterative Schemes for Ab Initio Total-Energy Calculations Using a Plane-Wave Basis Set. Phys. Rev. B: Condens. Matter Mater. Phys. 1996, 54 (16), 11169–11186. 10.1103/PhysRevB.54.11169. [DOI] [PubMed] [Google Scholar]
  27. Perdew J. P.; Burke K.; Ernzerhof M. Generalized Gradient Approximation Made Simple. Phys. Rev. Lett. 1996, 77 (18), 3865–3868. 10.1103/PhysRevLett.77.3865. [DOI] [PubMed] [Google Scholar]
  28. Blöchl P. E. Projector Augmented-Wave Method. Phys. Rev. B 1994, 50 (24), 17953–17979. 10.1103/PhysRevB.50.17953. [DOI] [PubMed] [Google Scholar]
  29. Kresse G.; Joubert D. From Ultrasoft Pseudopotentials to the Projector Augmented-Wave Method. Phys. Rev. B 1999, 59 (3), 1758–1775. 10.1103/PhysRevB.59.1758. [DOI] [Google Scholar]
  30. Monkhorst H. J.; Pack J. D. Special Points for Brillouin-Zone Integrations. Phys. Rev. B 1976, 13 (12), 5188–5192. 10.1103/PhysRevB.13.5188. [DOI] [Google Scholar]
  31. Dudarev S. L.; Botton G. A.; Savrasov S. Y.; Humphreys C. J.; Sutton A. P. Electron-Energy-Loss Spectra and the Structural Stability of Nickel Oxide: An LSDA+U Study. Phys. Rev. B 1998, 57 (3), 1505 10.1103/PhysRevB.57.1505. [DOI] [Google Scholar]
  32. Anisimov V. I.; Zaanen J.; Andersen O. K. Band Theory and Mott Insulators: Hubbard U Instead of Stoner I. Phys. Rev. B 1991, 44 (3), 943 10.1103/PhysRevB.44.943. [DOI] [PubMed] [Google Scholar]
  33. Fang Z.; Confer M. P.; Wang Y.; Wang Q.; Kunz M. R.; Dufek E. J.; Liaw B.; Klein T. M.; Dixon D. A.; Fushimi R. Formation of Surface Impurities on Lithium-Nickel-Manganese-Cobalt Oxides in the Presence of CO2 and H2O. J. Am. Chem. Soc. 2021, 143 (27), 10261–10274. 10.1021/jacs.1c03812. [DOI] [PubMed] [Google Scholar]
  34. Evans D. J.; Holian B. L. The Nose-Hoover Thermostat. J. Chem. Phys. 1985, 83 (8), 4069–4074. 10.1063/1.449071. [DOI] [Google Scholar]
  35. Tang W.; Sanville E.; Henkelman G. A Grid-Based Bader Analysis Algorithm without Lattice Bias. J. Phys.: Condens. Matter 2009, 21 (8), 084204 10.1088/0953-8984/21/8/084204. [DOI] [PubMed] [Google Scholar]
  36. Okhotnikov K.; Charpentier T.; Cadars S. Supercell Program: A Combinatorial Structure-Generation Approach for the Local-Level Modeling of Atomic Substitutions and Partial Occupancies in Crystals. J. Cheminf. 2016, 8 (17), 1–15. 10.1186/s13321-016-0129-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Zur A.; McGill T. C. Lattice Match: An Application to Heteroepitaxy. J. Appl. Phys. 1984, 55 (2), 378–386. 10.1063/1.333084. [DOI] [Google Scholar]
  38. Jetybayeva A.; Schön N.; Oh J.; Kim J.; Kim H.; Park G.; Lee Y. G.; Eichel R. A.; Kleiner K.; Hausen F.; Hong S. Unraveling the State of Charge-Dependent Electronic and Ionic Structure-Property Relationships in NCM622 Cells by Multiscale Characterization. ACS Appl. Energy Mater. 2022, 5 (2), 1731–1742. 10.1021/acsaem.1c03173. [DOI] [Google Scholar]
  39. Aribia A.; Sastre J.; Chen X.; Futscher M. H.; Rumpel M.; Priebe A.; Döbeli M.; Osenciat N.; Tiwari A. N.; Romanyuk Y. E. Unlocking Stable Multi-Electron Cycling in NMC811 Thin-Films between 1.5 – 4.7 V. Adv. Energy Mater. 2022, 12 (40), 2201750 10.1002/aenm.202201750. [DOI] [Google Scholar]
  40. Jain A.; Ong S. P.; Hautier G.; Chen W.; Richards W. D.; Dacek S.; Cholia S.; Gunter D.; Skinner D.; Ceder G.; Persson K. A. Commentary: The Materials Project: A Materials Genome Approach to Accelerating Materials Innovation. APL Mater. 2013, 1 (1), 1–11. 10.1063/1.4812323. [DOI] [Google Scholar]
  41. Zolotarev P. N.; Golov A. A.; Nekrasova N. A.; Eremin R. A. Topological Analysis of Procrystal Electron Densities as a Tool for Computational Modeling of Solid Electrolytes: A Case Study of Known and Promising Potassium Conductors. AIP Conf. Proc. 2019, 2163, 1 10.1063/1.5130086. [DOI] [Google Scholar]
  42. Golov A.; Carrasco J. Enhancing First-Principles Simulations of Complex Solid-State Ion Conductors Using Topological Analysis of Procrystal Electron Density. npj Comput. Mater. 2022, 8 (1), 1–10. 10.1038/s41524-022-00877-6. [DOI] [Google Scholar]
  43. GitHub- mcs-cice/IonExplorer2: IonExplorer2 - A Program for Calculation of Ion Diffusion Characteristics of Crystalline Ionconductors. https://github.com/mcs-cice/IonExplorer2 (accessed Sept 4, 2024).
  44. Jónsson H.; Mills G.; Jacobsen K. W.. Nudged Elastic Band Method for Finding Minimum Energy Paths of Transitions. In Classical and Quantum Dynamics in Condensed Phase Simulations; World Scientific, 1998; pp 385–404 10.1142/9789812839664_0016. [DOI] [Google Scholar]
  45. Henkelman G.; Uberuaga B. P.; Jónsson H. Climbing Image Nudged Elastic Band Method for Finding Saddle Points and Minimum Energy Paths. J. Chem. Phys. 2000, 113 (22), 9901–9904. 10.1063/1.1329672. [DOI] [Google Scholar]
  46. Golov A.; Carrasco J. Molecular-Level Insight into the Interfacial Reactivity and Ionic Conductivity of a Li-Argyrodite Li6PS5Cl Solid Electrolyte at Bare and Coated Li-Metal Anodes. ACS Appl. Mater. Interfaces 2021, 13 (36), 43734–43745. 10.1021/acsami.1c12753. [DOI] [PubMed] [Google Scholar]
  47. Zahiri B.; Patra A.; Kiggins C.; Yong A. X. B.; Ertekin E.; Cook J. B.; Braun P. V. Revealing the Role of the Cathode–Electrolyte Interface on Solid-State Batteries. Nat. Mater. 2021, 20 (10), 1392–1400. 10.1038/s41563-021-01016-0. [DOI] [PubMed] [Google Scholar]
  48. Van der Ven A.; Aydinol M.; Ceder G.; Kresse G.; Hafner J. First-Principles Investigation of Phase Stability in LixCoO2. Phys. Rev. B 1998, 58 (6), 2975–2987. 10.1103/PhysRevB.58.2975. [DOI] [Google Scholar]
  49. Riegger L. M.; Schlem R.; Sann J.; Zeier W. G.; Janek J. Lithium-Metal Anode Instability of the Superionic Halide Solid Electrolytes and the Implications for Solid-State Batteries. Angew. Chem., Int. Ed. 2021, 60 (12), 6718. 10.1002/anie.202015238. [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Lannelongue P.; Lindberg S.; Gonzalo E.; Golov A.; Bonilla F.; López del Amo J. M.; Marchandier T.; Tron A.; Carrasco J.; Lopez-Aranguren Oliver P.. Stable Cycling of halide solid state electrolyte enabled by a dynamic layered solid electrolyte interphase between Li metal and Li3YCl4Br2. Energy Storage Mater. 202427103733 10.1016/j.ensm.2024.103733. [DOI]
  51. Ren Y.; Liu J.; Zhang C.; Zhuang H.; Sun C.; Cai G.; Tan X.; Sun S. First-Principles Study of a Stable Anode Interface Based on the Electron Tunneling Effect to Suppress Transition Metal Reduction in Lithium Halide Solid-State Electrolytes. Chem. Eng. J. Adv. 2022, 12, 100377 10.1016/j.ceja.2022.100377. [DOI] [Google Scholar]
  52. Zhou H.; Yu S.; Liu H.; Liu P. Protective coatings for lithium metal anodes: Recent progress and future perspectives. J. Power Sources 2020, 450, 227632 10.1016/j.jpowsour.2019.227632. [DOI] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

am4c12938_si_001.pdf (1.5MB, pdf)

Articles from ACS Applied Materials & Interfaces are provided here courtesy of American Chemical Society

RESOURCES