A Co free Li and Mn-rich cathode Li_1.17Ni_0.25Mn_0.58O₂ is synthesized.

Galvanostatic cycling is tested with and without activation of this cathode material.

A specific capacity ≥240 mAh g⁻¹ is obtained in the potential range of 2.3–4.6 V.

The discharge voltage decay is suppressed by controlling the upper potential limit to 4.3 V.

An attractive low cost cathode material for Li-ion batteries is demonstrated.