Lithium Bromide-Induced Organic-Rich Cathode/Electrolyte Interphase for High-Voltage and Flame-Retardant All-Solid-State Lithium Batteries.

Poly(ethylene oxide) (PEO)-based solid electrolyte suffers from limited anodic stability and an intrinsic flammable issue, hindering the achievement of high energy density and safe all-solid-state lithium batteries. Herein, we surprisingly found out that a bromine-rich additive, decabromodiphenyl ethane (DBDPE), could be preferably oxidized at an elevated voltage and decompose to lithium bromide at an elevated potential followed by inducing an organic-rich cathode/electrolyte interphase (CEI) on NCM811 surface, enabling both high-voltage resistance (up to 4.5 V) and flame-retardancy for the PEO-based electrolyte. On the basis of this novel solid electrolyte, all-solid-state Li/NCM811 batteries deliver an average reversible capacity of 151.4 mAh g-1 over the first 150 cycles with high capacity retention (83.0%) and high average Coulombic efficiency (99.7%) even at a 4.5 V cutoff voltage with a unprecedented flame-retardant properties. In view of these exploration, our studies revealed the critical role of LiBr in inducing an organic-rich thin and uniform CEI passivating layer with enhanced lithium ion surface diffusion and high-voltage resistant properties, which provides a new protocol for the further design of a high-voltage PEO-based all-solid-state electrolyte.

NiFe Hydroxide Supported on Hierarchically Porous Nickel Mesh as a High-Performance Bifunctional Electrocatalyst for Water Splitting at Large Current Density.

The preparation of efficient and low-cost bifunctional catalysts with superior stability for water splitting is a topic of significant current interest for hydrogen generation. A facile strategy has been developed to fabricate highly active electrodes with hierarchical porous structures by using a two-step electrodeposition method, in which NiFe layered double hydroxide is grown in situ on a three-dimensional hierarchical Ni mesh (NiFe/Ni/Ni). The as-prepared NiFe/Ni/Ni electrodes demonstrate remarkable structural stability with high surface areas, effective gas transportation, and fast electron transfer. Benefiting from the unique structure, the self-supported NiFe/Ni/Ni electrodes exhibit overpotentials of 190 mV and 300 mV for the oxygen evolution reaction (OER) at current densities of 10 and 500 mA cm-2 , respectively. Furthermore, the self-supported NiFe/Ni/Ni electrodes also exhibit high performance in the hydrogen evolution reaction (HER) and excellent stability at a current density of 500 mA cm-2 for both OER and HER. Remarkably, using NiFe/Ni/Ni as both the cathode and anode for alkaline water electrolysis, a current density of 500 mA cm-2 is attained at a cell voltage of 1.96 V. Additionally, the water electrolyzer demonstrates superior stability even at a large current density (500 mA cm-2 ) when subjected to high temperatures.