Designed synthesis of layered double hydroxide cathode with multi-metal atom adulterated for aqueous zinc-ion batteries

Manganese oxides are widely investigated as cathodes for aqueous zinc-ion batteries (AZIBs). However, the tricky drawbacks of sluggish kinetics and irreversible structure degradation of manganese oxides usually lead to greatly decreased electrochemical activity and stability. Exploring novel Mn-based cathodes and comprehensively considering diverse charge storage mechanisms would be of enormous significance for the advancement of zinc-ion batteries. Herein, NiCoMnCu-based layered double hydroxide with N-doped C coated, naming as C/N-NiCoMnCu LDH, is designed and synthesized using rod-like structural CoMn-based oxalate as a precursor and template. Cu is artfully introduced during the polymerization process of polydopamine, which could also facilitate the polymerization. According to the electrochemical results, the multiple metal atom adulteration could distinctly improve the electrochemical activity and charge storage kinetics of the cathode. Along with the composition regulation, the designed nanosheet assembled structure is also proved to be of great efficiency to equalize the concentration and flux distribution, as well as the electric field distribution, which is conducive to promoting the interactions with charge carriers. Consequently, the electrochemical performance of the cathode could be effectively enhanced by composition and structure regulation. The assembled AZIB exhibits admirable specific capacity, rate performance, cycling stability, and energy density, which are superior to related works. This study puts forward a feasible method to prepare high-quality cathodes with both composition and structure regulated to optimize the electrochemical performance, which is of great significance for the advancement of AZIBs.