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

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 (Mn1−xVxO2) cathode, as an alternative to overcome the intrinsic limitations of conventional Zn–MnO2 batteries. Notably, Mn1−xVxO2 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 Mn1−xVxO2 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 Mn1−xVxO2 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 Mn1−xVxO2.