NiCo2O4/biomass-derived carbon composites as anode for high-performance lithium ion batteries

Low electronic conductivity and drastic volume change during cycling of transition metal oxides , as anodes for lithium ion batteries (LIBs), lead to rapid capacity decay and poor structural stability. Herein, nanostructured NiCo 2 O 4 anchored on carbon sheets was synthesized by a facile hydrothermal method with following thermal treatment. The wrinkled carbon substrate in the composite derives from the carbonization of pomelo peels, which can be mass-produced for the large-scale application. This composite shows mesoporous structures with high specific surface areas and intimate NiCo 2 O 4 /carbon interfaces, which favors the alleviation of the volume expansion/shrink during charging/discharging process and improves the electron/mass transport, enhancing the capability and stability for LIBs. This composite delivers a high reversible capacity of 473.7 mA h g −1 after 210 cycles at a current density of 500 mA g −1 . A long cycle life of up to 1100 cycles at 2000 mA g −1 is achieved with the retention capacity of 363 mA h g −1 . The electrode also exhibits excellent rate capability and can regain its original capacities as reversing to the low current densities . This work highlights the biomass-derived carbon-supported metal oxides as an environmentally friendly and economic strategy for advanced LIBs.