High-Entropy Disordered Rock-Salt Cathodes for Lithium-Ion Batteries

Traditional layered oxides consist of well-ordered alternating Li and transition metal (TM) with Li transport in two-dimensional (2D). In the disordered rock-salt (DRX) structure, Li and TM cations are randomly distributed at the 4a sites in the cationic sublattice.¹ The three-dimensional (3D) DRX cathodes are considerably more stable than the conventional layered oxides which often suffer from collapse of the interlayer spacing upon Li extraction at high voltages. The disordered arrangement of Li and TM opens the possibility of using a variety of TMs. The high-entropy DRX oxyfluorides, firstly reported by our group^2,3, of which the underlaying reaction mechanism has been intensively investigated recently especially by synchrotron-based techniques, including <i>operando</i> soft/hard X-ray absorption spectroscopy (XAS) and <i>ex situ</i> resonant inelastic X-ray scattering (RIXS).<br/><br/>References:<br/>Energy Environ. Sci. 13, 345–373 (2020)<br/>Energy Environ. Sci. 12, 2433–2442 (2019)<br/>Batter. Supercaps 3, 361–369 (2020)