A nanocomposite of MoO3 coated with polypyrrole (PPy) was prepared as an anode material for ARLBs. When nanochain LiMn2O4 is used as the cathode, the ARLB can deliver an energy density of 45 Wh kg−1 at 350 W kg−1 and even maintain 38 Wh kg−1 at 6 kW kg−1 in 0.5 M Li2SO4 aqueous electrolyte, corresponding to an good rate capability. In addition, its cycling behavior is greatly improved compared with the virginal MoO3. Our findings provide valuable clues to improve the comprehensive performance of ARLBs for practical application. This unique performance demonstrates that this battery will be of great promise as a power source for large power devices such as power loading and the storage of solar and wind energies.