Zhao Dong, Pu Xiangjun, Tang Shenglong, Ding Mingyue, Zeng Yubin, Cao Yuliang, Chen Zhongxue
Key Laboratory of Hydraulic Machinery Transients, Ministry of Education, School of Power and Mechanical Engineering, Wuhan University Wuhan 430072 China
College of Chemistry and Molecular Sciences, Wuhan University Wuhan 430072 China
Chem Sci. 2023 Jul 7;14(30):8206-8213. doi: 10.1039/d3sc02382f. eCollection 2023 Aug 2.
Aqueous zinc-ion batteries (AZIBs) with excellent safety, low-cost and environmental friendliness have great application potential in large-scale energy storage systems and thus have received extensive research interest. Layered oxovanadium phosphate dihydrate (VOPO·2HO) is an appealing cathode for AZIBs due to the unique layered framework and desirable discharge plateau, but bottlenecked by low operation voltage and unstable cycling. Herein, we propose delta-oxovanadium phosphate (δ-VOPO) without conventional pre-embedding of metal elements or organics into the structure and paired it into AZIBs for the first time. Consequently, superior to the layered counterpart, δ-VOPO exhibits better performance with a prominent discharge voltage of 1.46 V and a higher specific capacity of 122.6 mA h g at 1C (1C = 330 mA g), as well as an impressive capacity retention of 90.88 mA h g after 1000 cycles under 10C. By investigation of structure resolution and theoretical calculation, this work well elucidates the structure-function relationship in vanadyl phosphates, offering more chances for exploration of new cathode materials to construct high performance AZIBs.
具有卓越安全性、低成本和环境友好性的水系锌离子电池（AZIBs）在大规模储能系统中具有巨大的应用潜力，因此受到了广泛的研究关注。层状二水合氧钒磷酸（VOPO₄·2H₂O）因其独特的层状结构和理想的放电平台，是一种有吸引力的AZIBs正极材料，但受限于低工作电压和不稳定的循环性能。在此，我们提出了一种无需传统的金属元素或有机物预嵌入结构的δ-氧钒磷酸（δ-VOPO₄），并首次将其配对用于水系锌离子电池。因此，与层状对应物相比，δ-VOPO₄表现出更好的性能，在1C（1C = 330 mA g⁻¹）下具有1.46 V的突出放电电压和122.6 mA h g⁻¹的更高比容量，以及在10C下1000次循环后令人印象深刻的90.88 mA h g⁻¹的容量保持率。通过结构解析和理论计算研究，这项工作很好地阐明了钒基磷酸盐中的结构-功能关系，为探索新型正极材料以构建高性能水系锌离子电池提供了更多机会。
