O3/P2 mixed phase sodium-containing doped layered oxide materials

An O3/P2 mixed-phase sodium-containing doped layered oxide material which comprises a mixture of phases, wherein a first phase has one or more O3-type structures and a second phase has one or more P2-type structures;

• further wherein the O3/P2 mixed-phase sodium-containing doped layered oxide material has a general formula:
• NaaAbM1cM2dM3eM4fM5gO2±δ;
• wherein:
• A is an alkali metal selected from at least one of lithium and potassium;
• M1 is one or more metals with an average oxidation state of 2+ selected from nickel, iron, manganese, cobalt, copper, magnesium, calcium and zinc;
• M2 is one or more metals with an average oxidation state of 4+ selected from manganese, titanium and zirconium;
• M3 is one or more metals with an average oxidation state of 2+ selected from magnesium, calcium, copper, zinc and cobalt;
• M4 is one or more metals with an average oxidation state of 4+ selected from manganese, titanium and zirconium;
• and
• M5 is one or more metals with an average oxidation state of 3+ selected from aluminum, iron, cobalt, molybdenum, chromium, vanadium, scandium and yttrium;
• wherein:
• a>0;
• 0≤b<0.5;
• a>b;
• 0.75<(a+b)≤1.0;
• 0≤c<0.5;
• d≥0:
• f≥0;
• at least one of d and f is >0;
• e>0;
• 0≤g<0.5;
• 0≤δ≤0.1;
• wherein:
• a, b, c, d, e, f and g are chosen to maintain electroneutrality;
• wherein the O3/P2 mixed-phase sodium-containing doped layered oxide material comprises greater than 60 to 99% of the first phase, and less than 40 to 1% of the second phase, based on the combined total number of moles of the first and second phases present in the O3/P2 mixed-phase sodium-containing doped layered oxide material;
• and wherein the O3/P2 mixed-phase sodium-containing doped layered oxide material is neither a material with the general formula Na0.833Ni0.317Mn0.467Mg0.100Ti0.117O2 which comprises a mixture of phases in which a first phase has an O3-type structure and a second phase has a P2-type structure, wherein the amount of the first phase is 63% and the amount of the second phase is 37%, based on the combined total number of moles of the first and second phases present in the O3/P2 mixed-phase sodium-containing doped layered oxide material;
• nor a material with the general formula Na0.95Ni0.3167Mn0.3167Mg0.1583Ti0.2083O2 which comprises a mixture of phases in which a first phase has an O3-type structure and a second phase has a P2-type structure, wherein the amount of the first phase is 97% and the amount of the second phase is 3%, based on the combined total number of moles of the first and second phases in the O3/P2 mixed-phase sodium-containing doped layered oxide material.