Li Zixuan, Yuan Yi, Pu Shengda D, Qi Rui, Ding Shenghuan, Qin Runzhi, Kareer Anna, Bruce Peter G, Robertson Alex W
Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK.
School of Advanced Materials, Peking University Shenzhen Graduate School, Peking University, Shenzhen, 518055, China.
Adv Mater. 2024 Aug;36(32):e2401576. doi: 10.1002/adma.202401576. Epub 2024 Jun 12.
The value of aqueous zinc-ion rechargeable batteries is held back by the degradation of the Zn metal anode with repeated cycling. While raising the operating current density is shown to alleviate this anode degradation, such high cycling rates are not compatible with full cells, as they cause Zn-host cathodes to undergo capacity decay. A simple approach that improves anode performance while using more modest cathode-compatible current densities is required. This work reports reversible planar Zn deposition under cathode-compatible current densities can instead be achieved by applying external pressure to the cell. Employing multiscale characterization, this work illustrates how cycling under pressure results in denser and more uniform Zn deposition, analogous to that achieved under high cycling rates, even at low areal current densities of 1 to 10 mA cm. Microstructural mechanical measurements reveal that Zn structures plated under lower current densities are particularly susceptible to pressure-induced compression. The ability to achieve planar Zn plating at cathode-compatible current densities holds significant promise for enabling high-capacity Zn-ion battery full cells.
水系锌离子可充电电池的价值因锌金属阳极在反复循环过程中的降解而受到限制。虽然提高工作电流密度已被证明可以缓解这种阳极降解，但如此高的循环速率与全电池不兼容，因为它们会导致锌基阴极发生容量衰减。因此需要一种简单的方法来提高阳极性能，同时使用更适度的与阴极兼容的电流密度。这项工作报告称，通过对电池施加外部压力，反而可以在与阴极兼容的电流密度下实现可逆的平面锌沉积。利用多尺度表征，这项工作说明了在压力下循环如何导致更致密、更均匀的锌沉积，类似于在高循环速率下实现的沉积，即使在1至10 mA cm的低面电流密度下也是如此。微观结构力学测量表明，在较低电流密度下镀覆的锌结构特别容易受到压力诱导的压缩。在与阴极兼容的电流密度下实现平面锌电镀的能力对于实现高容量锌离子电池全电池具有重大前景。
