Calcium‐ion batteries (CIBs) are theoretically considered one of the potential post‐lithium‐ion battery technologies. However, only a few host materials are known to intercalate Ca ions. Herein, we demonstrate the use of double‐sheet vanadium oxide V₂O₅ ⋅ 0.63H₂O as a high‐performance cathode material for CIBs. The vanadium oxide was synthesized via an electrochemical oxidation process on a graphite foil substrate. The material exhibited a high reversible capacity of 204 mAh g⁻¹ at a 0.1 C rate in an aqueous electrolyte, with an average discharge voltage of 2.76 V vs. Ca/Ca²⁺, and a capacity retention of 86% after 350 cycles. The reaction mechanism can be described as a combination of diffusion‐controlled intercalation and surface‐limited pseudo‐capacitance reactions. This study provides a new type of Ca host material, motivating further development of new CIB cathode materials.

中文翻译：

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双片式氧化钒作为钙离子电池的阴极材料

从理论上讲，钙离子电池（CIB）是潜在的锂离子电池后技术之一。但是，已知仅有少数主体材料可插入Ca离子。这里，我们证明了使用双张氧化钒的V ₂ ø ₅  ⋅0.63H ₂ O作为用于CIBS高性能阴极材料。通过电化学氧化工艺在石墨箔基底上合成了钒氧化物。该材料在水性电解质中在0.1 C速率下表现出204 mAh g ^-1的高可逆容量，相对于Ca / Ca ²⁺的平均放电电压为2.76 V，并在350个循环后保持86％的容量。该反应机理可以描述为扩散控制插值和表面受限的假电容反应的组合。这项研究提供了一种新型的Ca基质材料，促进了新型CIB阴极材料的进一步开发。