Electrochemical characterization of nano V, Ti doped MnO₂ in primary lithium manganese dioxide batteries with high rate

Abstract

The nano-sized [Formula: see text]-MnO 2 precursor is synthesized using a room temperature, liquid-phase reaction route with the assistance of ultrasonic waves. The MnO 2 precursor as an electrode material in lithium manganese dioxide primary batteries displays a low capacity of 140[Formula: see text]mAh[Formula: see text]g[Formula: see text] (45.5% for the theoretical capacity of MnO[Formula: see text] at 20[Formula: see text]mA[Formula: see text]g[Formula: see text]. Therefore, the doped MnO 2 with cationic V or/and Ti are prepared at high temperature. After the heat treatment, the [Formula: see text] phase precursor powder gradually converts into the [Formula: see text]-MnO 2 and exhibits a higher specific surface area with a larger pore volume and pore size, providing significantly more electrochemically active sites for the redox reaction. The doped MnO 2 matrix has advantage of the ideal lattice parameters and the higher conductivity, resulting in an enhancement of the Li[Formula: see text] diffusion kinetics in the tunnel structure. Especially for co-doped MnO 2 with V and Ti, the modified material shows an outstanding electrochemical capacity of 190[Formula: see text]mAh[Formula: see text]g[Formula: see text] (61.7% for the theoretical capacity) at 20[Formula: see text]mA[Formula: see text]g[Formula: see text] and 169[Formula: see text]mAh[Formula: see text]g[Formula: see text] for a higher power output of 100[Formula: see text]mA[Formula: see text]g[Formula: see text].