The Li-ion paradigm of battery technology is constrained by the monovalency of the Li ion. A straightforward solution is to transition to multivalent-ion chemistries, where Mg²⁺ is the most obvious candidate because of its size and mass. The realization of Mg batteries has faced myriad obstacles, including a sparse selection of cathode materials demonstrating the ability to reversibly insert divalent ions. Here, we provide evidence of reversible topochemical and electrochemical insertion of Mg²⁺ into a metastable one-dimensional polymorph of V₂O₅ up to a capacity of 0.33 Mg²⁺ per formula unit. An electrochemical capacity of 90 mA hr g⁻¹ was retained after 100 cycles with an average operating potential of 1.65 V versus Mg²⁺/Mg⁰. Not only does ζ-V₂O₅ represent a rare addition to the pantheon of functional Mg battery cathode materials, but it is also distinctive in exhibiting a combination of high stability, high specific capacity, and moderately high operating voltage.

电池技术的锂离子范例受锂离子的单价性约束。一个简单的解决方案是过渡到多价离子化学，其中Mg ²⁺由于其尺寸和质量而成为最明显的候选物。镁电池的实现面临许多障碍，包括稀疏选择的阴极材料，证明了可逆地插入二价离子的能力。在这里，我们提供了Mg ²⁺可逆拓扑化学和电化学插入V ₂ O ₅的亚稳一维多晶型物的证据，容量高达每个配方单位0.33 Mg ²⁺。电化学容量为90 mA hr g ^-1在100个循环后保留的Mg 2 ⁺的平均工作电位为1.65 V对Mg ²⁺ / Mg ⁰。不仅ζ-V ₂ ø ₅代表一种罕见的除了官能镁电池正极材料神殿，但也表现出在高稳定性，高的比容量，和适度的高工作电压的组合独特的。