Hierarchical yolk-shell structured Li-rich cathode boosting cycling and voltage stabled LIBs

Despite the high energy density of lithium-rich(Li-rich)cathodes,their implementation is hampered by the unsatisfied rate capacity and poor cycling performance accompanied with substantial voltage decay.To address these issues,the hierarchical yolk-shell structured Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)cathodes(YK-LMNCO)was proposed and synthesized through a facile glycerol assisted solvothermal approach and the following lithiation process.Benefitting from the shortened lithium diffusion lengths and the enhanced tolerance to the large volume variation upon lithium ions intercalation/de-intercalation,the unique structure reciprocates an initial coulombic efficiency of 85.8%,an outstanding capacity retention rate of 89.1%after cycling at 2.0 C for 200 cycles with a minor voltage drop,and a capacity retention rate of 93.8%after cycling at 10.0 C for 500 cycles,85.2%for 1,000 cycles.When assembled with graphite as anode,the YK-LMNCO//graphite full cell shows a remarkable capacity retention rate of 87.2%after cycling at 5.0 C for 50 cycles.Our facile strategy for constructing the yolk-shell structured Li-rich cathodes with high capacity and voltage stability sheds light on synthesizing other lithium storage materials.