Li-storage of Li2ZnTi3O8@C-N anodes with high-performance in a wide temperature range

Abstract

Spinel Li2ZnTi3O8 (LZTO) with a zero volumetric change, exhibits high safety as an anode of lithium-ion batteries. Nevertheless, the low electrical conductivity restricts its wide application. A facile one-step solid-state route has been used to synthesize LZTO@C-N composites with different N content. The existence of N-doped carbon improves the diffusion coefficients of Li+ ions and the electronic conductivity, and reduces the charge-transfer resistance and the side reactions between electrolyte and LZTO. The N content can affect the lattice constants and the appearance the new phases. The LZTO@C-N-2 composite with the proper N content of 2.2 w.% possesses the best electrochemical performance in wide temperature range from 0 to 55°C. Discharging at 2 A g− 1 and charging at 0.5 A g− 1, 219.7 and 214.8 mAh g− 1 are obtained for LZTO@C-N-2 at the 1st and 150th cycles, respectively, with small capacity fade at 25°C. 290.3 and 151 mAh g− 1 are delivered at the 1st and 150th cycles for LZTO@C-N-2 at 55°C, respectively. Even at 0°C, the LZTO@C-N-2 composite still shows good rate capability. The simple synthetic route and good electrochemical performance enable LZTO@C-N-2 to be a potential anode of LIBs.