Facile Al2O3 coating suppress dissolution of Mn2+ in Mn-substituted Na3V2(PO4)3 with outstanding electrochemical performance for full sodium ion batteries

Chenghao Qian; Mengna Shi; Chunfang Fan; Changcheng Liu; Que Huang; Yanjun Chen

doi:10.1016/j.jcis.2024.03.072

Facile Al₂O₃ coating suppress dissolution of Mn²⁺ in Mn-substituted Na₃V₂(PO₄)₃ with outstanding electrochemical performance for full sodium ion batteries

J Colloid Interface Sci. 2024 Jun 15:664:573-587. doi: 10.1016/j.jcis.2024.03.072. Epub 2024 Mar 12.

Authors

Chenghao Qian¹, Mengna Shi¹, Chunfang Fan², Changcheng Liu³, Que Huang⁴, Yanjun Chen⁵

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 North University of China, Taiyuan 030051, Shanxi, People's Republic of China.
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. Electronic address: ccliu@nuc.edu.cn.
⁴ 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.
⁵ 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: 38490033
DOI: 10.1016/j.jcis.2024.03.072

Abstract

Na₃V₂(PO₄)₃ (NVP) encounters significant obstacles, including limited intrinsic electronic and ionic conductivities, which hinder its potential for commercial feasibility. Currently, the substitution of V³⁺ with Mn²⁺ is proposed to introduce favorable carriers, enhancing the electronic conductivity of the NVP system while providing structural support and stabilizing the NASICON framework. This substitution also widens the Na⁺ migration pathways, accelerating ion transport. Furthermore, to bolster stability, Al₂O₃ coating is applied to suppress the dissolution of transition metal Mn in the electrolyte. Notably, the Al₂O₃ coating serves a triple role in reducing HClO₄ concentration in the electrolyte, inhibiting Mn dissolution, and functioning as the ion-conducting phase. Likewise, carbon nanotubes (CNTs) effectively hinder the agglomeration of active particles during high-temperature sintering, thereby optimizing the conductivity of NVP system. In addition, the excellent structural stability is investigated by in situ XRD measurement, effectively improving the volume collapse during Na⁺ de-embedding. Moreover, the Na₃V_5.92/3Mn_0.04(PO₄)₃/C@CNTs@1wt.%Al₂O₃ (NVMP@CNTs@1wt.%Al₂O₃) possesses unique porous structure, promoting rapid Na⁺ transport and increasing the interface area between the electrolyte and the cathode material. Comprehensively, the NVMP@CNTs@1wt.%Al₂O₃ sample demonstrates a remarkable reversible specific capacity of 122.6 mAh/g at 0.1 C. Moreover, it maintains a capacity of 115.9 mAh/g at 1 C with a capacity retention of 90.2 mAh/g after 1000 cycles. Even at 30 C, it achieves a capacity of 87.9 mAh/g, with a capacity retention rate of 84.87 % after 6000 cycles. Moreover, the NVMP@CNTs@1wt.%Al₂O₃//CHC full cell can deliver a high reversible capacity of 205.5 mAh/g at 0.1 C, further indicating the superior application potential in commercial utilization.

Keywords: Al(2)O(3) coating; CNTs; Mn doping and dissolution; Na(3)V(2)(PO(4))(3); Porous configuration.