Abstract
With its unique 3D skeleton structure and exceptional cyclic stability,the Na+superionic conductor(NASICON)-type Na3V2(PO4)2F3(NVPF)has been con-sidered as a competitive cathode material for advanced Na-ion batteries.However,the release of fluorine during the heat treatment leads to the formation of an additional phase Na3V2(PO4)3(NVP),which results in a low-voltage plateau and compromises the energy density.Herein,we modulate the local electronic states of the V site by aluminum sub-stitution to strengthen the stability of F.The results confirm that the aluminum introduction not only changes the local electron states of V sites,significantly reducing the for-mation of NVP by-product from 6.71 wt％to 1.01 wt％,but also effectively reduces the band gap,improving the electronic conductivity of NVPF.The optimized Na3V1.9A10.1(PO4)2F3 exhibits higher energy density of 340 Wh-kg-1 and excellent rate performance of 106.7 mAh·g-1 at 10C compared with the pristine cathode.
基金项目
National Natural Science Foundation of China(52064049)
National Natural Science Foundation of China(52372232)
Major Science and Technology Projects of Yunnan Province(202302AB080019-3)
National Natural Science Foundation of Yunnan Province(202301AS070040)
National Natural Science Foundation of Yunnan Province(202301AU070209)
Scientific Research Fund Project of Yunnan Provincial Department of Education(2023J0033)
NETL
NSTL
万方数据