Development of next generation batteries is predicated on the design and discovery of new, functional materials. Divalent cations are promising options that go beyond the canonical Li-based systems, but the development of new materials for divalent ion batteries is hindered due to difficulties in promoting divalent ion conduction. We have developed a family of cathode materials based on the divalent cation conductor ZnPS₃. Substitution of V for Zn in the lattice concomitant with vacancy introduction yields isostructural but redox-active materials that can reversibly store Zn^2 + in the vacancies. A range of voltammetry and galvanostatic cycling experiments along with x-ray photoelectron spectroscopy support that redox is indeed centered on V and that capacity is dependent on the V content. The voltage of the materials is limited by the irreversible decomposition of the polyanion above 1.4 V vs. Zn/Zn^2 +. The reversible capacity before anion decomposition is limited to half the vacancies and is due to the relative ratios of oxidized and reduced V centers. Such observations provide useful design rules for cathode materials for divalent cation based battery technologies, and highlight the necessity for a holistic interpretation of physical and electronic structural changes upon cycling.

下一代电池的开发取决于新型功能材料的设计和发现。二价阳离子是超越基于锂的典型体系的有前途的选择，但是由于难以促进二价离子的传导，阻碍了用于二价离子电池的新材料的开发。我们已经开发了基于二价阳离子导体ZnPS ₃的阴极材料系列。用V代替晶格中的Zn随空位引入而产生同构但具有氧化还原活性的材料，可以可逆地存储Zn ^{2 +}在空缺。一系列伏安法和恒电流循环实验以及X射线光电子能谱均支持氧化还原确实以V为中心，而容量取决于V含量。材料的电压受到高于1.4 V相对于Zn / Zn ^{2 +}的聚阴离子不可逆分解的限制。阴离子分解之前的可逆容量限制为空位的一半，这是由于氧化和还原的V中心的相对比率所致。这样的观察为基于二价阳离子的电池技术的阴极材料提供了有用的设计规则，并强调了对循环时物理和电子结构变化进行整体​​解释的必要性。