A non-aqueous Li+/Cl− dual-ion battery with layered double hydroxide cathode

CoFe-Cl LDH was firstly applied in a novel Li+/Cl− dual-ion battery in LiCl/DMSO electrolyte with good high current discharge capacity (137 mAh/g@1 A/g), large diffusion coefficient (10−12∼10−14), and low cost. This work is of great significance to the development of new type dual-ion batteries. [Display omitted] •A dual-ion battery (DIB) with LiCl electrolyte was constructed for the first time.•This DIB has a high Cl− storage capacity with outstanding power density (1770 W/kg) and energy density (240 Wh/kg).•This work broadens the use of layered double hydroxides in electrochemistry. Dual-ion batteries (DIBs) have unique advantages in energy storage, such as high energy density and low cost. However, most studies on organic DIBs use anions with a large ionic radius (PF6−, TFSI−, etc.). Here, we propose a Li+/Cl− dual-ion battery (DIB) through using CoFe-Cl layered double hydroxides (LDHs) and non-aqueous LiCl electrolytes, with a mechanism involving anionic insertion into the LDHs cathode and lithium plating/stripping on the anode. Coupled X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques indicate reversible expansion/extraction of (003) crystal planes of LDHs and valence state changes of Co and Fe, enabling high Cl− storage capacities of 145 mAh/g and 137 mAh/g at 200 mA/g and 1 A/g, respectively. Furthermore, this DIB demonstrates an impressive power density of 1770 W/kg with an energy density of 240 Wh/kg. This work provides a reference for developing high performance DIBs and expands the electrochemical application field of LDHs.