Table 7.

Comparison of different light-assisted flexible energy storage systems

Light-assisted flexible energy storage system types	Advantages	Disadvantages	Application scenarios
SC	Extremely high power density and fast charging–discharging speed Extremely long cycle life and excellent bending resistance of flexible substrates (such as carbon cloth and polymers) Light-assisted enhancement of the double layer/pseudocapacitive effect through photo-generated charges, improving specific capacitance Simple structure and low cost	Low energy density, far below that of battery systems Long-term exposure to light may cause photo-corrosion of electrode materials, affecting service life Energy storage mechanism relies on surface reactions, limiting capacity improvement potential	Flexible wearable sensors (such as heart rate and body temperature monitoring devices), high-frequency charging and discharging devices (foldable keyboards, flexible displays)
Li–O2 battery	Extremely high theoretical energy density, with light assistance reducing overpotential during charging and discharging Photocatalytic enhancement of ORR/OER activity, improving energy conversion efficiency Compatible with flexible substrates, with excellent bending performance	Poor cycle stability Lithium dendrite issues have not been completely resolved, posing safety hazards Flexible substrates (such as polyimide) may be swollen by the electrolyte, affecting mechanical stability	High-energy demand flexible devices (such as flexible drone power supplies and foldable solar power banks)
Li–CO2 battery	High theoretical energy density, light assistance can promote CO2 reduction reaction kinetics, suitable for CO2 recycling in enclosed spaces Flexible structure and good compatibility with solid electrolytes, excellent bend resistance	CO₂ diffusion is greatly affected by deformation, and the bending angle is limited The cycle life is extremely short, CO2 adsorption/desorption efficiency is low, and by-products (Li2C3) are difficult to decompose Photocatalytic materials are easily eroded by Li+, resulting in poor long-term stability	Flexible energy storage in closed environments (such as flexible sensor power supplies for space stations and flexible equipment for deep-sea exploration)
Li–S battery	High theoretical energy density Photocatalytic inhibition of polysulfide shuttling, greatly extending cycle life Abundant sulfur resources, good compatibility between flexible substrates and sulfur electrodes	High volume expansion rate, flexible structures are prone to cracking due to expansion Limited light response wavelength, weak enhancement effect under visible light Some light-responsive materials are toxic, limiting biocompatibility	Medium- to high-energy flexible wearable devices (such as smart bracelets and flexible electronic skin power supplies)
Li–N2 battery	Raw material (N2) is inexhaustible (air source) and theoretically suitable for long-term energy storage Light assistance can activate the inert bond of N₂ (lowering the activation energy) and preliminarily achieve the N2 reduction reaction	The reaction kinetics are extremely poor, and the energy conversion efficiency is low The cycle life is extremely short	Specialized energy storage applications (e.g., flexible backup power sources for aerospace and deep-sea exploration)
Zn battery	Water-based electrolyte (high safety, no risk of combustion or explosion), abundant zinc resources (low cost) Light assistance can increase the oxygen evolution overpotential, inhibit water decomposition, and improve cycle life Excellent mechanical flexibility	Low energy density and limited low-temperature performance ORR/OER kinetics still need to be improved	Everyday flexible electronics (such as flexible watches and smart clothing power sources)
Mg battery	Rich in magnesium resources (low cost), high volumetric energy density Better safety than lithium-based batteries Excellent flexibility and structural stability	Limited choice of cathode materials, limited improvement with light assistance Low energy density, insufficient competitiveness Poor electrolyte compatibility	Low-cost flexible electronics (flexible remote controls, electronic tags, foldable card-type devices)
Sn battery	The theoretical capacity of tin negative electrode is relatively high, and light assistance can suppress tin volume expansion and improve cycle life Tin resources are abundant and the cost is moderate No dendrite risk, good safety Good compatibility with flexible substrates	Low energy density Limited bending angle, average deformation tolerance	Medium–low endurance flexible devices (flexible keyboards, electronic skin, smart curtain sensors)