Se-induced defective carbon nanotubes promoting superior kinetics and electrochemical performance in Na3V2(PO4)3 for half and full Na ion cells

Haodi Dong; Changcheng Liu; Que Huang; Yanjun Chen

doi:10.1016/j.jcis.2024.01.087

Se-induced defective carbon nanotubes promoting superior kinetics and electrochemical performance in Na₃V₂(PO₄)₃ for half and full Na ion cells

J Colloid Interface Sci. 2024 Apr 15:660:277-289. doi: 10.1016/j.jcis.2024.01.087. Epub 2024 Jan 13.

Authors

Haodi Dong¹, Changcheng Liu², Que Huang³, Yanjun Chen⁴

Affiliations

¹ School of Environment and Safety Engineering, North University of China, Taiyuan 030051, Shanxi, People's Republic of China; Institute of Advanced Energy Materials and Systems, North University of China, Taiyuan 030051, Shanxi, People's Republic of China.
² School of Environment and Safety Engineering, North University of China, Taiyuan 030051, Shanxi, People's Republic of China; Institute of Advanced Energy Materials and Systems, North University of China, Taiyuan 030051, Shanxi, People's Republic of China. Electronic address: ccliu@nuc.edu.cn.
³ School of Environment and Safety Engineering, North University of China, Taiyuan 030051, Shanxi, People's Republic of China; Institute of Advanced Energy Materials and Systems, North University of China, Taiyuan 030051, Shanxi, People's Republic of China; School of Resources and Safety Engineering, Central South University, Changsha 410010, Hunan, People's Republic of China. Electronic address: que.huang@nuc.edu.cn.
⁴ Institute of Advanced Energy Materials and Systems, North University of China, Taiyuan 030051, Shanxi, People's Republic of China; School of Materials Science and Engineering, North University of China, Taiyuan 030051, Shanxi, People's Republic of China. Electronic address: yjchen@nuc.edu.cn.

PMID: 38244495
DOI: 10.1016/j.jcis.2024.01.087

Abstract

Na₃V₂(PO₄)₃ (NVP), with unique Na super ionic conductivity (NASICON) framework, has become an prospective cathode material. However, the low electronic conductivity and poor structural stability limit its further development. Currently, the optimized carbon nanotubes (CNTs) by selenium doping are utilized to modify NVP system for the first time. Notably, the introduction of selenium in CNTs promotes to generate more defects, resulting in abundant active sites for the de-intercalation of Na⁺ to achieve more pseudocapacitance. Moreover, the newly formative C-Se bonds possess much stronger bond energy than the original CC (586.6 KJ mol^-1 vs 377.4 KJ mol^-1) bonds. The structure arrangement of the original CNTs is significantly improved by the doped selenium element, indicating that an enhanced carbon skeleton could be obtained to sustain the structural stability of NVP system. Furthermore, the excess selenium can be doped into the bulk of NVP crystal to replace of partial oxygen. Due to the larger ionic of Se^2- (1.98 Å vs 1.4 Å of O^2-), the VSe₆ group has larger framework, which provides a broadened pathway for Na⁺ migration to improve the kinetic characteristics. Accordingly, the modified NVP@CNTs:Se = 1:1 sample exhibits superior rate capability and cyclic performance. It reveals high capacities of 78.6 and 76.5 mAh/g at 20 and 60C, maintaining 65.4 and 53.8 mAh/g after 5000 and 7000 cycles with high capacity retention of 84.49 % and 70.32 %, respectively. The assembled NVP@CNTs:Se = 1:1//CHC full cell delivers a high value of 153.6 mAh/g, suggesting the optimized sample also behaves excellent application potentials.

Keywords: Carbon nanotubes; Full cells; Kinetics; Na(3)V(2)(PO(4))(3); Se-induced.