Structurally reconstituted calcium manganate nanoparticles as a high-performance cathode for aqueous Zn-ion batteries

Abstract

The low capacity and poor cycling performance severely restrict the further development of Mn-based materials for aqueous Zn-ion batteries (AZIBs). Finding effective strategies to address these issues is urgent but still challenging for the design of high-performance cathodes. Here, we developed Ca-deficient Ca_0.96Mn_3.04O₄ nanoparticles (denoted as CP-CMO) by a simple structural reconstitution strategy to achieve high capacity and long cycling durability in AZIBs. The unique nanoparticle architecture endows the CP-CMO sample with improved electrical conductivity and enhanced structural stability, and accelerates the diffusion rate of Zn ions. Correspondingly, the Zn//CP-CMO battery based on the CP-CMO cathode delivers a favorable capacity of 231.1 mA h g⁻¹ at 0.2 mA cm⁻², good rate performance, excellent cyclic lifespan and great coulombic efficiency (close to 100%). Moreover, the battery device also exhibits a satisfactory energy density of 299.5 W h kg⁻¹ and a peak power density of 512.5 W kg⁻¹. This work offers an excellent example of using structural recombination strategy to develop high-performance cathode materials for AZIBs.