Enabling robust anionic redox structure via tuning the symmetry of locally ordered lattice in Li-rich Li-Mn-O cathodes

•A tLR-LMO cathode with a twofold symmetry locally ordered lattice was designed.•The tLR-LMO shows a high capacity of 260 mAh g−1 and excellent cycling stability.•The superior properties originate from the stable ARR structure.•Robust ARR structure is related to the twofold symmetry locally ordered lattice.•Tuning structure symmetry provides a bright way for optimizing layered cathodes.