Effect of non-stoichiometry on the charge storage capacity of NiO conversion anodes in Li-ion batteries

conversion anodes comprising non-stoichiometric black nio suffer severe capacity fading in li-ion batteries despite having a high li+ ion diffusion coefficient. we attribute this capacity fading to (i) its small crystallite size (~ 8 nm) and (ii) high charge transfer resistance (rct ~ 60–180 ω cm2). small crystallites enhance grain boundaries which promote li+ ion diffusion without efficient material utilization. in contrast, the stoichiometric green nio anodes deliver a stable capacity of 280 mah g−1 over 50 charge-discharge cycles. the comparatively higher capacity of green nio can be explained from its (i) large crystallite size (~ 104 nm) and (ii) negligible rct values.