Controlled Prelithiation of SnO2/C Nanocomposite Anodes for Building Full Lithium-Ion Batteries.

SnO2 is an attractive anodic material for advanced lithium-ion batteries (LIBs). However, its low electronic conductivity and large volume change in lithiation/delithiation lead to a poor rate/cycling performance. Moreover, the initial Coulombic efficiencies (CEs) of SnO2 anodes are usually too low to build practical full LIBs. Herein, a two-step hydrothermal synthesis and pyrolysis method is used to prepare a SnO2/C nanocomposite, in which aggregated SnO2 nanosheets and a carbon network are well-interpenetrated with each other. The SnO2/C nanocomposite exhibits a good rate/cycling performance in half-cell tests but still shows a low initial CE of 45%. To overcome this shortage and realize its application in a full-cell assembly, the SnO2/C anode is controllably prelithiated by the lithium-biphenyl reagent and then coupled with a LiCoO2 cathode. The resulting full LIB displays a high capacity of over 98 mAh g-1LCO in 300 cycles at 1 C rate.