Proton-selective coating enables fast-kinetics high-mass-loading cathodes for sustainable zinc batteries.

Guo, Quanquan; Li, Wei; Li, Xiaodong; Zhang, Jiaxu; Sabaghi, Davood; Zhang, Jianjun; Zhang, Bowen; Li, Dongqi et al. · Nat Commun · 2024

basic_science · Level V

Where this comes from

Abstract

The pressing demand for sustainable energy storage solutions has spurred the burgeoning development of aqueous zinc batteries. However, kinetics-sluggish Zn<sup>2+</sup> as the dominant charge carriers in cathodes leads to suboptimal charge-storage capacity and durability of aqueous zinc batteries. Here, we discover that an ultrathin two-dimensional polyimine membrane, featured by dual ion-transport nanochannels and rich proton-conduction groups, facilitates rapid and selective proton passing. Subsequently, a distinctive electrochemistry transition shifting from sluggish Zn<sup>2+</sup>-dominated to fast-kinetics H<sup>+</sup>-dominated Faradic reactions is achieved for high-mass-loading cathodes by using the polyimine membrane as an interfacial coating. Notably, the NaV<sub>3</sub>O<sub>8</sub>·1.5H<sub>2</sub>O cathode (10 mg cm<sup>-2</sup>) with this interfacial coating exhibits an ultrahigh areal capacity of 4.5 mAh cm<sup>-2</sup> and a state-of-the-art energy density of 33.8 Wh m<sup>-2</sup>, along with apparently enhanced cycling stability. Additionally, we showcase the applicability of the interfacial proton-selective coating to different cathodes and aqueous electrolytes, validating its universality for developing reliable aqueous batteries.