Duan Yixue, Li Bolong, Yang Kai, Gong Zheng, Peng Xuqiao, He Liang, Ho Derek
School of Mechanical Engineering, State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, Sichuan University, Chengdu, 610065, People's Republic of China.
Department of Materials Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong, 999077, People's Republic of China.
Nanomicro Lett. 2024 Nov 29;17(1):79. doi: 10.1007/s40820-024-01586-z.
Aqueous Ni-Zn microbatteries are safe, reliable and inexpensive but notoriously suffer from inadequate energy and power densities. Herein, we present a novel mechanism of superoxide-activated Ni substrate that realizes the redox reaction featuring three-electron transfers (Ni ↔ Ni). The superoxide activates the direct redox reaction between Ni substrate and KNiO by lowering the reaction Gibbs free energy, supported by in-situ Raman and density functional theory simulations. The prepared chronopotentiostatic superoxidation-activated Ni (CPS-Ni) electrodes exhibit an ultrahigh capacity of 3.21 mAh cm at the current density of 5 mA cm, nearly 8 times that of traditional one-electron processes electrodes. Even under the ultrahigh 200 mA cm current density, the CPS-Ni electrodes show 86.4% capacity retention with a Columbic efficiency of 99.2% after 10,000 cycles. The CPS-Ni||Zn microbattery achieves an exceptional energy density of 6.88 mWh cm and power density of 339.56 mW cm. Device demonstration shows that the power source can continuously operate for more than 7 days in powering the sensing and computation intensive practical application of photoplethysmographic waveform monitoring. This work paves the way to the development of multi-electron transfer mechanisms for advanced aqueous Ni-Zn batteries with high capacity and long lifetime.
水系镍锌微型电池安全、可靠且成本低廉，但能量和功率密度却一直不足。在此，我们提出了一种超氧化物激活镍基底的新机制，实现了具有三电子转移（Ni ↔ Ni）的氧化还原反应。原位拉曼光谱和密度泛函理论模拟表明，超氧化物通过降低反应吉布斯自由能，激活了镍基底与镍酸钾之间的直接氧化还原反应。制备的恒电位超氧化激活镍（CPS-Ni）电极在5 mA cm的电流密度下表现出3.21 mAh cm的超高容量，几乎是传统单电子过程电极的8倍。即使在200 mA cm的超高电流密度下，CPS-Ni电极在10000次循环后仍保持86.4%的容量，库仑效率为99.2%。CPS-Ni||Zn微型电池实现了6.88 mWh cm的卓越能量密度和339.56 mW cm的功率密度。器件演示表明，该电源在为光电容积脉搏波监测这一传感和计算密集型实际应用供电时，可连续运行超过7天。这项工作为开发具有高容量和长寿命的先进水系镍锌电池的多电子转移机制铺平了道路。
