Operando electrochemical fluorination to achieve Mn 4+ /Mn 2+ double redox in a Li 2 MnO 3 -like cathode

The drastic changes (Li 2 MnO 3 →Li 1.67 MnO 2.1 F 0.2 ) in the first cycle of Li 2 MnO 3 -like through oxygen release (O 2− →O 2 ) and in operando F-doping, activated a two-electron redox of Mn 4+/2+ with a capacity of 326 mA h g −1 .