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

• DOI: 10.1021/acsami.0c08205
• Publication Date: 2020-07-09T11:39:28Z
• Authors: Wanhai Zhou; Jian He; Ding Zhu; Jinchi Li; Yungui Chen
• Keywords: Nanosheet; Power density; Kirkendall Effect

Zn-based aqueous batteries are enjoying the hotspots of worldwide research as their significant merits in economic cost and safety. However, lack a robust cathode (positive electrode) owning excellent rate ability, high capacity, stability challenges practical application. Herein, we propose hierarchical NiSe2 nanosheet arrays toward high-performance Ni-Zn batteries. Attributed to situ anion exchange Kirkendall effects, hierarchically constructed by nanoparticles abundant mesopores, which fully expose active sites accelerate electrode kinetics. This unique structure endows with remarkable specific capacity (245.1 mAh g-1) extraordinary high-rate ability (maintains 58% at 72.8 A together 10,000 cycles without any obvious degeneration. As result, based on total weight, our NiSe2//Zn battery is capable record-high power density (91.22 kW kg-1/639.1 mW cm-2), imposing energy (328.8 Wh kg-1/2.303 mWh ultralong lifespan (only 8.3% loss after cycles), surpassing most supercapacitors recently reported. Moreover, this also affordable (US$40 per kWh) safe. These results open new avenue for developing superdurable ultrafast high-energy storage.