北京科技大学刘永畅揭示了水溶液锌-二氧化锰电池阴离子氧化还原化学。相关研究成果于2024年8月12日发表在《德国应用化学》。

由于在高工作电压下具有迷人的额外容量，激活阴离子氧化还原反应（ARR）引起了人们对Li/Na离子电池的极大兴趣。然而，ARR在水性锌离子电池（AZIBs）中很少被报道，其在流行的MnO₂基阴极中的可能性尚未得到探索。

该文通过低温（140°C）水热法制备了具有层间“Ca²⁺柱”（CaMnO-140）的新型缺锰MnO₂微纳球，其中Mn空位可以通过产生非键合O 2p态来触发ARR，预嵌入的Ca²⁺可以通过形成CaO构型来增强层状结构并抑制晶格氧释放。定制的CaMnO-140阴极在AZIBs中表现出前所未有的高倍率性能（0.1 A g^-1时为485.4 mAh g^-1，10 A g^-1时154.5 mAh g^-1）和出色的长期循环耐久性（5000次循环后容量保持率为90.6%）。

通过先进的同步加速器表征和理论计算，阐明了伴随着CF₃SO₃（从电解质中）吸收/释放的可逆氧氧化还原化学，以及伴随着H⁺/Zn²⁺共插入/提取的锰氧化还原。最后，袋式CaMnO-140//Zn电池具有高能量、长寿命、宽温度适应性和高操作安全性等优点，具有广阔的应用前景。

该研究通过引发阴离子氧化还原化学，为开发AZIBs的高能阴极提供了新的视角。

附：英文原文

Title: Unraveling the Anionic Redox Chemistry in Aqueous Zinc-MnO2 Batteries

Author: Tianhao Wang, Junteng Jin, Xudong Zhao, Xuanhui Qu, Lifang Jiao, Yongchang Liu

Issue&Volume: 2024-08-12

Abstract: Activating anionic redox reaction (ARR) has attracted a great interest in Li/Na-ion batteries owing to the fascinating extra-capacity at high operating voltages. However, ARR has rarely been reported in aqueous zinc-ion batteries (AZIBs) and its possibility in the popular MnO2-based cathodes has not been explored. Herein, the novel manganese deficient MnO2 micro-nano spheres with interlayer “Ca2+-pillars” (CaMnO-140) are prepared via a low-temperature (140 °C) hydrothermal method, where the Mn vacancies can trigger ARR by creating non-bonding O 2p states, the pre-intercalated Ca2+ can reinforce the layered structure and suppress the lattice oxygen release by forming CaO configurations. The tailored CaMnO-140 cathode demonstrates an unprecedentedly high rate capability (485.4 mAh g1 at 0.1 A g1 with 154.5 mAh g1 at 10 A g1) and a marvelous long-term cycling durability (90.6% capacity retention over 5000 cycles) in AZIBs. The reversible oxygen redox chemistry accompanied by CF3SO3 (from the electrolyte) uptake/release, and the manganese redox accompanied by H+/Zn2+ co-insertion/extraction, are elucidated by advanced synchrotron characterizations and theoretical computations. Finally, pouch-type CaMnO-140//Zn batteries manifest bright application prospects with high energy, long life, wide-temperature adaptability, and high operating safety. This study provides new perspectives for developing high-energy cathodes for AZIBs by initiating anionic redox chemistry.

DOI: 10.1002/anie.202412057

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202412057