3D printing of customized MnO2 cathode for aqueous zinc-ion batteries
(1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China)
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract: In order to overcome the problems of inferior cycling stability and slow ion diffusion of MnO2 cathode in aqueous zinc-ion battery, a high-accuracy customized 3D printed MnO2 cathode was prepared via direct ink writing. The rheological test showed that the printing ink indicated shear-thinning behavior with the storage modulus platform value over 105 Pa. The SEM images displayed that the customized mesh-layer structure was well maintained after 100 cycles. The 3D structure with excellent mechanical strength could effectively alleviate the internal stress and provide a greater specific surface area. The specific capacity of the 3D printing cathode was three times higher than that of the 2D one at 50 mA/g after 110 stable cycles. The energy storage mechanism of the reversible Mn2+/Mn4+ double redox for 3D printing battery was also studied through a variety of ex-situ experiments.
Key words: α-MnO2; aqueous zinc-ion batteries; 3D printing; direct ink writing; energy storage mechanism