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 Li1.2Mn0.54Ni0.13Co0.13O2 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.

Automated summary

The hierarchical yolk-shell structured Li1.2Mn0.54Ni0.13Co0.13O2 cathode shows an initial coulombic efficiency of 85.8% and outstanding capacity retention rates of 89.1% after cycling at 2.0 C for 200 cycles. After cycling at 10.0 C for 500 cycles, the capacity retention rate is 93.8%, and for 1,000 cycles, it is 85.2%.