Na2.4Al0.4Mn2.6O7 anionic redox cathode material for sodium-ion batteries – a combined experimental and theoretical approach to elucidate its charge storage mechanism

Al substitution and subsequent Na excess in Na 2 Mn 3 O 7 were achieved by a ceramic method, realizing the high-performance Na 2.4 Al 0.4 Mn 2.6 O 7 oxygen-redox cathode for Na-ion batteries. A comparison between the two cathodes revealed the role of Al doping.