Controlling interlayer spacing and chemical bond to enhance the electronic and ionic of <scp> Delta‐MnO <sub>2</sub> </scp> as <scp>Zinc‐ion</scp> batteries cathode
Jianhua Zhang, Wenbin Li, Jingjing Wang, Xiaohua Pu, Gaini Zhang, Shuai Wang, Ni Wang, Xifei Li
Abstract
The low electrical and ionic conductivity of the δ-MnO2 cathode material cause its sluggish charge transport kinetics with poor rate capability for zinc-ion batteries (ZIBs). Herein, K+ and Na+ are successfully pre-intercalated into the interlayer of δ-MnO2 possessing the morphology of nanosheets self-assembled flower-like submicrosphere. Compared with Na+, the pre-intercalation of K+ synchronously optimizes the interlayer spacing as well as Mn–O bond and hence facilitates the electronic and ionic conductivity with enhancing rate capability. At a rate of 3 A g−1, the specific capacity of K+ pre-intercalated δ-MnO2 cathode reaches 100.1 mAh g−1 after 600 cycles. Meanwhile, a diffusion-controlled and intercalation pseudocapacitive charge storage process is revealed at lower and higher potential scans, respectively. The research results provide a potential strategy for Zn2+ storage property improvement of layered metallic oxide cathodes.