High-entropy strategy to suppress volumetric strain and enhance diffusion rate of Na3V2(PO4)2F3 cathode for durable and high-areal-capacity zinc-ion battery pouch cells
Jia Xu, Musanna Galib, Zhenrui Wu, Tao Li, Yijia Shao, Yue Zhang, Xiaolong Guo, Evan J. Hansen, Yujin Chen, Zhenbo Wang, Chang Liu, Mauricio Ponga, Jian Liu
Abstract
Aqueous zinc-ion batteries are pivotal contributors to the global energy transformation. Cathode materials with NASICON-type structures are promising candidates for zinc-ion batteries but are hindered by their low electrical conductivity , sluggish ionic diffusion, and structural instability. This work introduces a high-entropy, carbon-coated NASICON-type Na 3 V 2 (PO 4 ) 2 F 3 (HE-NVPF@C) cathode by incorporating five metal elements (Al, Zn, Mn, Cr, and Nb) mainly into the V sites of the VO 4 F 2 octahedral structure. Systematic experimental and simulation studies of the Zn 2+ storage mechanism in high-entropy NASICON-type cathode are presented for the first time. The high-entropy doping strategy contributes to significantly enhanced cycling stability by suppressing Jahn-Teller distortion, reducing lattice change during Zn 2+ extraction and insertion, and decreasing the Zn 2+ migration energy barrier. As a result, the HE-NVPF@C cathode demonstrates exceptional cycling stability over 6000 cycles at 20 C with a capacity loss of a mere 0.0031 % per cycle and a high areal capacity retention of 2.17 mAh cm −2 . In addition, the pouch cell provides a long cycling lifespan with 90.8 % capacity retention at 5 C after 200 cycles. This feasible high-entropy approach broadens the perspective for developing practical zinc-ion batteries with a long cycle lifespan and high areal capacity.