The specific capacity of Li0.44Mn1−y Ti y O2 (0< y <0.22) positive electrode materials has been improved by an additional lithium-insertion treatment in molten LiNO3–LiOH salt at a low temperature. High-purity specimens of the lithium-inserted Li0.44+x Mn1−y Ti y O2 have been successfully prepared. We have conducted a systematic experimental study of the structural and electrochemical properties of these compounds. The inserted lithium content, x, in Li0.44+x Mn1−y Ti y O2 increases together with the substituted Ti content, y. The initial charge capacity increases from 130mAhg−1 (y =0) to 145mAhg−1 (y =0.22) for the Li0.44+x Mn1−y Ti y O2 compounds. The maximum discharge capacity that has been achieved is 180mAhg−1 in the case of Li0.72Mn0.78Ti0.22O2 between 2.5 and 4.8V with a fixed current density of 30mAg−1 (C/6) at 30°C. The discharge capacity at the 4V plateau region (about 100mAhg−1) in the lithium-inserted Li0.55MnO2 has been improved to twice that in as-prepared Li0.44MnO2 (about 50mAhg−1). The structural differences between Li0.44MnO2 and Li0.55MnO2 are discussed based on XRD Rietveld analysis results.