Lattice engineering in MnO2via V5+ doping for high-performance aqueous Te–MnO2 batteries

Abstract

Aqueous zinc–manganese dioxide (Zn–MnO₂) batteries hold great promises for large-scale energy storage but face several challenges, such as dendrite formation on the anode and structural instability of the cathode. Herein, we propose an aqueous tellurium–manganese dioxide (Te–MnO₂) battery, which employs carbon-supported tellurium (C@Te) to replace the Zn metal anode coupled with vanadium-doped MnO₂ (Mn_1−xV_xO₂) cathode, as an alternative to overcome the intrinsic limitations of conventional Zn–MnO₂ batteries. Notably, Mn_1−xV_xO₂ can be produced through a room-temperature redox method, enabling effective V⁵⁺ ion doping in various α-, β-, γ-, and δ-MnO₂ polymorphs. The resulting Mn_1−xV_xO₂ exhibits enhanced structural stability due to the suppressed Jahn–Teller distortion and improved electronic conductivity resulting from V 3d/O 2p orbital hybridization. Consequently, the Mn_1−xV_xO₂ cathode delivers a high specific capacity of 323.7 mAh g⁻¹ at 0.1 A g⁻¹ and 93.5% capacity retention after 1000 cycles at 0.5 A g⁻¹, which significantly surpass those of the pristine MnO₂ (P-MnO₂). Mechanistic investigations and theoretical calculations further unveil a synergistic mechanism involving enhanced electron transport, optimized ion adsorption, and improved structural stability, demonstrating that V⁵⁺ doping promotes reversible H⁺/Zn²⁺ co-intercalation. Our study shows that Te–MnO₂ batteries can offer a viable alternative to conventional Zn–MnO₂ batteries and afford a universal synthesis strategy for Mn_1−xV_xO₂.