Liang Wenhao, Rao Dewei, Chen Tao, Tang Rongfeng, Li Jun, Jin Huile
CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui, P. R. China.
Institute of Energy, Hefei Comprehensive National Science Center, Hefei, China.
Angew Chem Int Ed Engl. 2022 Aug 26;61(35):e202207779. doi: 10.1002/anie.202207779. Epub 2022 Jul 7.
Developing cathode materials integrating good rate performance and sufficient cycle life is the key to commercialization of aqueous zinc-ion batteries. The hyperstable Zn V O ⋅1.8 H O (ZVOH) cathode with excellent rate performance has been successfully developed via an in situ self-transformation from zinc-rich Zn V O (ZVO) in this study. Different from the common synthetic method of additional Zn pre-insertion, ZVOH is obtained from the insertion of structural H O and the removal of excess Zn in ZVO, ensuring the lattice structure of ZVOH remains relatively intact during the phase transition and rendering good structural stabilities. The ZVOH delivers a reversible capacity of 286.2 mAh g at 0.2 A g and of 161.5 mAh g at 20 A g over 18 000 cycles with a retention of 95.4 %, demonstrating excellent rate performance and cyclic stability. We also provide new insights on the structural self-optimization of Zn (CF SO ) (OH) ⋅n H O byproducts and the effect on the mobility of Zn by theoretical calculations and experimental evidence.
开发兼具良好倍率性能和足够循环寿命的正极材料是水系锌离子电池商业化的关键。本研究通过富锌的ZnVO（ZVO）原位自转变成功开发出了具有优异倍率性能的超稳定ZnVO·1.8H₂O（ZVOH）正极。与常见的额外预插入锌的合成方法不同，ZVOH是通过结构中H₂O的插入和ZVO中过量锌的去除而获得的，这确保了ZVOH在相变过程中晶格结构保持相对完整，并具有良好的结构稳定性。ZVOH在0.2 A g下可逆容量为286.2 mAh g，在20 A g下18000次循环后可逆容量为161.5 mAh g，容量保持率为95.4%，展现出优异的倍率性能和循环稳定性。我们还通过理论计算和实验证据，对Zn（CF₃SO₃）（OH）·nH₂O副产物的结构自优化及其对锌迁移率的影响提供了新的见解。
