In/Ce Co-doped Li<sub>3</sub>VO<sub>4</sub> and Nitrogen-modified Carbon Nanofiber Composites as Advanced Anode Materials for Lithium-ion Batteries
Yuanlang Wan, Zhi Chang, Xuefang Xie, Jialin Li, Simin Chai, Shuang Zhou, Qiong He, Chunyan Fu, Mingyang Feng, Guozhong Cao, Shuquan Liang, Anqiang Pan
Abstract
Li3VO4 (LVO) is considered as a novel alternative anode material for lithium-ion batteries (LIBs) due to its high capacity and good safety. However, the inferior electronic conductivity impedes its further application. Here, nanofibers (nLICVO/NC) with In/Ce co-doped Li3VO4 strengthened by nitrogen-modified carbon are prepared. Density functional theory calculations demonstrate that In/Ce co-doping can substantially reduce the LVO band gap and achieve orders of magnitude increase (from 2.79 × 10–4 to 1.38 × 10–2 S cm–1) in the electronic conductivity of LVO. Moreover, the carbon-based nanofibers incorporated with 5LICVO nanoparticles can not only buffer the structural strain but also form a good framework for electron transport. This 5LICVO/NC material delivers high reversible capacities of 386.3 and 277.9 mA h g–1 at 0.1 and 5 A g–1, respectively. Furthermore, high discharge capacities of 335 and 259.5 mA h g–1 can be retained after 1200 and 4000 cycles at 0.5 and 1.6 A g–1, respectively (with the corresponding capacity retention of 98.4 and 78.7%, respectively). When the 5LICVO/NC anode assembles with commercial LiNi1/3Co1/3Mn1/3O2 (NCM111) into a full cell, a high discharge capacity of 191.9 mA h g–1 can be retained after 600 cycles at 1 A g–1, implying an inspiring potential for practical application in high-efficiency LIBs.