Physicochemically Interlocked Selenium for High Performing Aqueous Zinc-Selenium Batteries

A conversion-chemistry-based zinc-selenium aqueous battery is reported that delivers high specific capacity, good rate capability, and excellent cycle life. In this work, an electronically conjugated covalent triazine framework is used to physicochemically lock selenium (Se8) clusters. As a control sample, the traditional melt-diffusion approach is used to physically lock Se8. While the melt-diffused selenium cathode exhibited a precipitous drop in capacity with cycling, the physicochemically locked selenium cathode can be cycled in a stable manner and delivered a specific capacity of approximate to 600 mAh g-1 with a capacity retention of approximate to 70% after 1000 continuous charge/discharge steps. Ab initio density functional theory calculations and various structural and morphological characterizations indicate that the superiority of the physicochemically locked selenium cathode stems from its ability to suppress the polyselenide shuttle phenomenon and thus prevent loss of active material during cycling. This work opens the door toward the development of conversion chemistries for high performing, non-flammable, and low-cost zinc-based rechargeable batteries. An electronically conjugated covalent triazine framework is reported that physicochemically locks selenium clusters, enabling a conversion-chemistry based zinc-selenium aqueous battery that delivers high specific capacity, good rate capability, and long cycle life. image