Sc and Zn were introduced into O3-NaMn0.5Ni0.5O2(NaMN)using the combination of solution combustion and solid-state method.The effect of Sc and Zn dual-substitution on Na+diffusion dynamics and structural stability of NaMN was investigated.The physicochemical characterizations suggest that the introduction of Sc and Zn broaden Na+diffusion channels and weaken the Na—O bonds,thereby facilitating the diffusion of sodium ions.Simulations indicate that the Sc and Zn dual-substitution decreases the diffusion barrier of Na-ions and improves the conductivity of the material.The dual-substituted NaMn0.5Ni0.4Sc0.04Zn0.04O2(NaMNSZ44)cathode delivers impressive cycle stability with capacity retention of 71.2％after 200 cycles at 1C and 54.8％after 400 cycles at 5C.Additionally,the full cell paired with hard carbon anode exhibits a remarkable long-term cycling stability,showing capacity retention of 64.1％after 250 cycles at 1C.These results demonstrate that Sc and Zn dual-substitution is an effective strategy to improve the Na+diffusion dynamics and structural stability of NaMN.
关键词
层状氧化物正极/Sc和Zn双取代/结构稳定性/Na+扩散动力学
Key words
layered oxide cathode/Sc and Zn dual-substitution/structural stability/Na diffusion dynamics
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基金项目
National Natural Science Foundation of China(52377220)
Natural Science Foundation of Hunan Province,China(kq2208265)
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