Table 2.

Site-specific quantitative APT results along the depth of pristine Li(Ni_0.80Co_0.15Mn_0.05)O₂ (NCM) and NCM subjected to the formation, 100 cycles and 300 cycles (the atomic ratio is normalised to obtain a total metal fraction of 1).

Specimen		Atomic ratio
Process	Region (depth from the surface)	Li	Ni	Co	Mn	O
NCM-pristine	R (from surface to centre)	1.03	0.84	0.12	0.04	1.94
NCM formation	R (from surface to centre)	0.96	0.81	0.15	0.05	1.89
NCM-100 cycles	R1 (< 100 nm)	0.57	0.79	0.16	0.05	1.85
	R2 (~200 nm)	0.68	0.79	0.16	0.05	1.90
	R3 (~300 nm)	0.76	0.79	0.16	0.05	1.73
	R4 (~2 μm)	0.99	0.79	0.16	0.05	1.92
NCM-300 cycles	R0 (surface)	0.03	0.81	0.16	0.03	1.63
	R1 (< 30 nm)	0.37	0.81	0.14	0.05	1.88
	R2 (~100 nm)	0.47	0.83	0.13	0.04	1.84
	R3 (~350 nm)	0.69	0.81	0.14	0.05	1.86
	R4 (~700 nm)	0.77	0.82	0.14	0.04	1.79
	R5 (~1.0 μm)	0.84	0.80	0.15	0.05	1.91
	R6 (~1.5 μm)	0.91	0.82	0.14	0.04	1.94
	R7 (~2.5 μm)	1.03	0.82	0.14	0.04	1.91