P2-type Na2/3Ni1/3Mn2/3−xTixO2 as a new positive electrode for higher energy Na-ion batteries

New electrode material of layered oxide, Na_2/3Ni_1/3Mn_1/2Ti_1/6O₂, delivers 127 mA h g⁻¹ of reversible capacity and the average voltage reaches 3.7 V with good capacity retention in an aprotic Na cell.