Enhanced cycling stability of single-crystal LiNi_(0.83)Co_(0.07)Mn_(0.10)O_(2)by Li-reactive coating with H_(3)BO_(3)

Ni-rich cathode materials will be primarily used as next-generation high-specific energy cathode materials in lithium-ion batteries.However,residual Li formation and cracking considerably restrict the wide application of these materials.To address the issues related to cracking,micro-sized single-crystal cathode materials without internal grain boundaries are proposed.In this study,we constructed a thin LiBO_(2)layer on the single-crystal LiNi_(0.83)Co_(0.07)Mn_(0.10)O_(2)particles by solvent-free H_(3)BO_(3)modification.The residual Li on the material surface decreased by 14%through the reaction of LiOH/Li_(2)CO_(3)and H_(3)BO_(3).The coated materials exhibited higher initial Coulombic efficiency(88.44%),higher reversible capacity(213.4 mAh·g^(-1)at 0.1 C),and better cycling performance(91.31%retention over 50 cycles within 3.0-4.3 V at 1.0C)than the unmodified materials.Using the galvanostatic intermittent titration technique,electrochemical impedance spectroscopy(EIS),and inductively coupled plasma-optical emission spectroscopy(ICP-OES),we reveal the mechanism by which the electrochemical properties are improved upon H_(3)BO_(3)modification.The superior electrochemical performances are associated with increased Li+conductivity,lower charge transfer impedance,and suppressed transition metal dissolution.Therefore,this study demonstrates the importance of surface modification in obtaining Ni-rich single-crystal materials with enhanced performance.