Interfacial strain induced crystalline-amorphous nanoarchitectures anchoring MoO42− anionic groups to alleviate self-discharge of battery-type cathodes

Abstract

Battery-type cathodes that endow supercapacitors (SCs) with high energy density have severe self-discharge defect. However, the underlying origin and regulation strategy have never been reported. In this work, we proposed an advanced in-situ anionic group anchoring strategy utilizing the strain effect between external NCZ-LDH and internal NiMoO4. Combining experiments with theoretical calculation, we confirmed that the self-discharge behavior of battery-type cathodes is highly related with the dissociation reaction of H2O in fully charged state, while the defect can be significantly alleviated through the modification of MoO42− in the reconstructed strain induced crystalline-amorphous nanoarchitectures, which optimizes the adsorption and dissociation energies of H2O. As a result, the NiMoO4@NCZ-LDH electrode not only exhibits excellent capacity and durability, but also significantly increases capacity retention from 21.3 % to 79.7 % after self-discharge for 72 h and keeps in a high open circuit potential throughout. This study fills the blank of battery-type cathodes in self-discharge research and points out a promising direction for designing high performance SCs.