Hierarchical yolk-shell structured Li-rich cathode boosting cycling and voltage stabled LIBs
Yanchen Liu, Yafen Chen, Jing Wang, Wei Wang, Zhiyu Ding, Leyuan Li, Yang Zhang, Yida Deng, Junwei Wu, Yanan Chen, Yanan Chen, Yanan Chen
Abstract
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.