Environmentally responsible synthesis of high-performance P2-Na 2/3 [Ni 1/3 Mn 2/3 ]O 2 sodium-ion battery cathodes

An environmentally responsible synthesis of Na 2/3 [Ni 1/3 Mn 2/3 ]O 2 (NNMO) enabled by direct conversion of metallic Ni powder, releasing only O 2 and H 2 O as byproducts. The resulting NNMO exhibits excellent cycling performance as a Na-ion battery cathode.