Conformal Prelithiation Nanoshell on LiCoO2 Enabling High-Energy Lithium-Ion Batteries

The initial lithium loss in lithium-ion batteries (LIBs) reduces their energy density (e.g., 15% or higher for LIBs using a Si-based anode). Herein, we report in situ chemical formation of a conformal Li2O/Co nanoshell nm) on LiCoO2 particles as a high-capacity built-in prelithiation reagent to compensate this initial lithium loss. We show a 15 mAh g(-)(1) increase in overall charge capacity for the LiCoO2 with 1.5 wt % Li2O/Co in comparison to the pristine LiCoO2 in virtue of the irreversible lithium extraction from the nanoshell (4Li(2)O + 3Co -> 8Li(+) + 8e(-) + Co3O4, 2Li(2)O -> 4Li(+) + 4e(-) + O-2 up arrow). Paired with a graphite-SiO anode, a full cell using such a LiCoO2 cathode demonstrates 11% higher discharge capacity (2.60 mAh cm(-2)) than that using pristine LiCoO2 (2.34 mAh cm(-2)) at 0.1 C, as well as stable battery cycling. Moreover, the prelithiated LiCoO2 is compatible with the current battery fabrication process.