Improved Na storage performance of Na₃V₂(PO₄)₃ cathode material for sodium-ion batteries by K-Cl co-doping

Abstract

As a promising cathode material for sodium-ion batteries (SIBs), Na3V2(PO4)3 (NVP), the typical NASICON (Na super-ionic conductor)-structure cathode material, has received much attention resulting from its high working potential and excellent structural stability. However, it has always suffered from low electroconductivity, which largely limits its application in SIBs. Herein, to improve the electrochemical performance, we developed potassium and chlorine co-doped Na3V2(PO4)3/carbon particles (NKVPCl/C) using a spray-drying method combined with a calcinating process and adopted them as cathode materials for SIBs. We studied in detail how K+ and Cl− affected the electrochemical performance. The NKVPCl/C-2 particles displayed a highly initial discharge capacity of 109.6 mA h g−1 at 0.2 C, and had a superior cycling stable property (nearly 100% of initial discharge capacity after 500 cycles at 5 C). The excellent electrochemical performance of NKVPCl/C can be attributed to its higher Na+ diffusion and electron conduction, which indicates that the strategy of co-doping K-Cl is an effective tactic for improving the property of NVP in SIBs.

Construction of metal–organic framework-derived Al-doped Na 3V 2(PO 4) 3 cathode materials for high-performance rechargeable Na-ion batteries

“…Therefore, these results demonstrate that NVAP2 is a durable and reversible cathode for SIBs. Figure 4f indicates that the rate capability of NVAP2 was superior to those of previously reported materials [57][58][59][60][61] .…”

Unfolding the structural features of NASICON materials for sodium‐ion full cells

“…However, practical applications are still limited because of the poor intrinsic electronic conductivity (10 −6 – 10 −8 S cm −1 ) 38,39 . Several methods have been used to improve the electronic conductivity of NASICON materials by combining with carbon‐based materials, 40–42 elemental doping, 43–47 and designing 3D porous architectures 48–51 …”

“…[31][32][33][34][35][36][37] However, practical applications are still limited because of the poor intrinsic electronic conductivity (10 −6 -10 −8 S cm −1 ). 38,39 Several methods have been used to improve the electronic conductivity of NASICON materials by combining with carbon-based materials, [40][41][42] elemental doping, [43][44][45][46][47] and designing 3D porous architectures. [48][49][50][51] In this review, we focus on the recent progress and limitations of NASICON structured electrode materials, which include phosphates (Na x M 2 (PO 4 ) 3 ), fluorophosphate (Na x M 2 (PO 4 ) 2 F), binary transition-metal phosphates (Na x MMʹ(PO 4 ) 2 F), and mixed phosphates (Na x M 2 (PO 4 )(SO 4 ) 2 and Na x M 2 (PO 4 ) 2 P 2 O 7 ) for SIBs.…”