Ca/Ni Codoping Enables the Integration of High-Rate and High-Capacity Zn-Ion Storage Performances for Layered Hydrated Vanadate

作者：Xia, Xue; Yun, Juwei; Huang, Cheng; Li, Deli; Yang, Zeheng; Huang, Haijian^*; Zhang, Weixin^*

来源：Industrial and Engineering Chemistry Research, 2022, 61(12): 4212-4221.

DOI：10.1021/acs.iecr.2c00220

• CHEMISTRY
• CATHODE
• CHALLENGES
• BATTERIES
• CARBON
• WATER

Layered hydrated vanadates have been regarded aspromising cathode materials for Zn-ion batteries, while theirelectrochemical properties have been proved to be highly related tothe species of the interlayer cations. However, because the singlespecies of the interlayer cation can hardly endow the layeredmaterials with comprehensively favorable properties, the introduc-tion of multiple interlayer cations may offer an avenue to furtheroptimization of the Zn-ion storage performance. Herein, this workintroduces the codoping of Ca/Ni-ions in the structure of hydratedvanadate (Ca0.19Ni0.08V2O5middot0.85H2O), which not only upgrades thespecific capacities but also gives rise to high rate and cyclingperformances. Specifically, the interlayer Ni-ion in the structureplays a vital role in contributing to the high charge storagecapability via participating in the electrochemical reactions. Meanwhile, the Ca-ion could stably act as pillars, pinning the adjacentVOxlayers and thus leading to the structural stability of the layered material during operation. Moreover, the synergistic effects ofthe codoping result in the enlarged lattice spacing, which incurs the nearly zero-strain structural evolution processes with solid-solution-like charge storage behaviors. Accordingly, on the basis of a multiple-ion doping strategy, this study offers an effectiveapproach to further boost the Zn-ion storage performance of hydrated vanadates