Boosting Zn2+ Intercalation in High-Performance Aqueous Zinc-Ion Batteries with Coupling-Induced Biphase Interface.

Effectively addressing the trade-off between fast charging kinetics and long cycle life of aqueous zinc ion batteries (AZIBs) has proven challenging due to JahnTeller distortion and high lattice strain induced by inserted Zn2+ ions in cathode structures. Herein, a hybrid cathode of NiCo2O4-MnO2 with abundant electrochemical phase interfaces and interface coupling induced defects is developed via a simple electrochemical oxidation strategy to boost rich redox reactions. The formation of Ni─O─Mn and Co─O─Mn bonds promoted the electron transfer between the biphase interface, adjusted the electron density of the material body, effectively alleviated the electrostatic effect between Zn2+ embedding and the main frame, and further maintained the stability of the structure and alleviated the dissolution of manganese. The resulting NiCo2O4-MnO2 cathode exhibited a high reversible specific capacity of 343.5 mA h g-1 at a current density of 100 mA g-1 and retained 95.5 % of its initial capacity after 1000 cycles at a current density of 1 A g-1. This discovery enriches insights into performance mechanisms at interfaces and paves the way for designing advanced energy storage materials.

A Comparatively Low Cost, Easy-To-Fabricate, and Environmentally Friendly PVDF/Garnet Composite Solid Electrolyte for Use in Lithium Metal Cells Paired with Lithium Iron Phosphate and Silicon.

Solid electrolytes may be the answer to overcome many obstacles in developing the next generation of renewable batteries. A novel composite solid electrolyte (CSE) composed of a poly(vinylidene fluoride) (PVDF) base with an active nanofiber filler of aluminum-doped garnet Li ceramic, Li salt lithium bis-(trifluoromethanesulfonyl)imide (LiTFSI), Li fluoride (LiF) stabilizing additive, and plasticizer sulfolane was fabricated. In a Li|CSE|LFP cell with this CSE, a high capacity of 168 mAh g-1 with a retention of 98% after 200 cycles was obtained, representing the best performance to date of a solid electrolyte with a PVDF base and a garnet inorganic filler. In a Li metal cell with Si and Li, it yielded a discharge capacity of 2867 mAh g-1 and was cycled 60 times at a current density of 100 mAh g-1, a significant step forward in utilizing a solid electrolyte of any kind with the desirable Si anode. In producing this CSE, the components and fabrication process were chosen to have a lower cost and improved safety and environmental impact compared with the current state-of-the-art Li-ion battery.