Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, China.
Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China.
Adv Mater. 2019 Dec;31(52):e1905873. doi: 10.1002/adma.201905873. Epub 2019 Nov 11.
Building aqueous acidic batteries is in its infancy. There are several sporadic attempts that show desirable electrochemical performance, especially rate stability and high power density. The direct use of a metal anode is regarded as the best protocol for fabricating metal-based batteries. However, introducing an acid-tolerant and electrochemically reversible metal anode into an acidic aqueous battery system remains a considerable challenge. In this work, copper (Cu) metal is used as a reversible metal anode to match acidic regimes with a nearly 100% deposition-dissolution efficiency. The reaction kinetics and mechanism of the Cu anode can be regulated by protons with 400% kinetic acceleration compared with a mild electrolyte. In addition, the anode exhibits a dendrite-free morphology after cycling due to the surface roughening effect, which is different from the morphologies of widely used Zn- and Li-metal anodes. When coupled with the Prussian blue analog as cathodes, the battery delivers ultrafast kinetics of 1830 W kg at 75 C, which is comparable to the power performance of supercapacitors. Long-term cyclic stability is evaluated, where the capacity retention is 85.6% after 5000 cycles. Finally, flexible fiber-shaped acidic Cu-based batteries are demonstrated for potential wearable applications.
水系酸性电池仍处于起步阶段。有一些零星的尝试表明其具有理想的电化学性能，特别是倍率稳定性和高功率密度。直接使用金属阳极被认为是制造金属基电池的最佳方案。然而，将耐酸和电化学可逆的金属阳极引入酸性水系电池系统仍然是一个相当大的挑战。在这项工作中，铜（Cu）金属被用作可逆金属阳极，以与酸性条件相匹配，实现近 100%的沉积-溶解效率。Cu 阳极的反应动力学和机制可以通过质子来调节，与温和的电解质相比，其动力学加速了 400%。此外，由于表面粗糙化效应，阳极在循环后呈现出无枝晶形态，这与广泛使用的 Zn 和 Li 金属阳极的形态不同。当与普鲁士蓝类似物作为阴极结合时，电池在 75°C 下的超快动力学达到 1830 W kg，可与超级电容器的功率性能相媲美。对其长期循环稳定性进行了评估，在 5000 次循环后，容量保持率为 85.6%。最后，展示了用于潜在可穿戴应用的柔性纤维状酸性 Cu 基电池。
