An aqueous rechargeable lithium battery (ARLB) consisting of a combination of polyaniline (PANI) anode, LiMn2O4 cathode, and a saturated LiNO3 aqueous electrolyte has been constructed. The charge/discharge process of the battery is associated with the doping/un-doping of anions at the anode and intercalation/deintercalation of lithium ions at the cathode. This battery exhibits excellent electrochemical performance. The average discharge voltage of the PANI//LiMn2O4 battery is about 1.1V. During initial 52 cycles, there is an activation process for this battery. After the 52nd cycle, it continues to run 98 cycles, which makes the battery only loses 18.6% of its discharge capacity. The battery delivers a capacity of 89.9mAhg−1 at the 150th cycle. This technology solves the major problem of poor cycling life of ARLBs and enlarges the application of PANI.