Hierarchical NiSe2 Nanosheet Arrays as a Robust Cathode toward Superdurable and Ultrafast Ni–Zn Aqueous Batteries

作者：Wanhai Zhou, Jian Xin He, Ding Zhu, Jinchi Li, Yungui Chen · 发表于：ACS Applied Materials & Interfaces · 年份：2020 · DOI：10.1021/acsami.0c08205 · 被引用次数：67 · 研究领域：Advanced battery technologies research、Supercapacitor Materials and Fabrication、Advanced Battery Materials and Technologies

Zn-based aqueous batteries are enjoying the hotspots of worldwide research as their significant merits in economic cost and safety. However, the lack of a robust cathode (positive electrode) owning excellent rate ability, high capacity, and stability challenges their practical application. Herein, we propose hierarchical NiSe 2 nanosheet arrays as a robust cathode toward high-performance Ni–Zn aqueous batteries. Attributed to in situ anion exchange and Kirkendall effects, the nanosheet arrays are hierarchically constructed by NiSe 2 nanoparticles and abundant mesopores, which fully expose the active sites and accelerate the electrode kinetics. This unique structure endows the NiSe 2 electrode with remarkable specific capacity (245.1 mAh g –1 ) and extraordinary high-rate ability (maintains 58% at 72.8 A g –1 ) together with 10,000 cycles without any obvious capacity degeneration. As a result, based on the total active weight, our NiSe 2 //Zn battery is capable of record-high power density (91.22 kW kg –1 /639.1 mW cm –2 ), imposing energy density (328.8 Wh kg –1 /2.303 mWh cm –2 ), and ultralong lifespan (only 8.3% capacity loss after 10,000 cycles), surpassing most of the aqueous batteries and supercapacitors recently reported. Moreover, this NiSe 2 //Zn battery is also affordable (US$40 per kWh) and safe. These results open a new avenue for developing superdurable and ultrafast high-energy Ni–Zn batteries toward affordable and practical energy storage.