Boosting Electrochemical Performance of Ni-rich Layered Cathode Via Li2SnO3 Surface Coating and Sn<SUP>4+</SUP> Gradient Doping Based Dual Modification for Lithium-ion Batteries

초록

Ni-rich ternary oxide cathode (LiNi0.8Co0.1Mn0.1O2, NCM) is highly promising candidate for lithium-ion batteries (LIBs) due to its relatively large specific capacity and high energy density. Nevertheless, intrinsic structural/chemical instability and unwanted side reactions on the surface during charge/discharge, leading to rapid capacity fading and inferior cycle performance, severely impeded its commercialization. Herein, we demonstrated an interfacial/surface dual modification strategy, one of the most important techniques for fabricating LiNi0.8Co0.1Mn0.1O2, NCM cathode materials via Li2SnO3 surface coating and Sn4+ gradient doping. The electrochemical results deliver that the Sn dual-modified NCM exhibits the highest discharge capacity of 86.5% at 6.0 C and superior initial discharge capacity of 177.8 mAh g(-1). In addition, Sn-modified NCM811 cathode shows an improved reversible capacity of 144.9 mAh g(-1) and excellent electrode kinetics after 200 cycles. The dual modification strategy proposes a novel approach that can accelerate commercialization by simultaneously alleviating the surface instability and bulk structural degradation of Ni-rich cathode materials for state-of-the-art LIBs. [GRAPHICS] .

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