Exciton Dissociation into Charge Carriers in Porphyrinic Metal-Organic Frameworks for Light-Assisted Li-O Batteries.

Light-assisted Li-O batteries exhibit a high round-trip efficiency attributable to the assistance of light-generated electrons and holes in oxygen reduction and evolution reactions. Nonetheless, the excitonic effect arising from Coulomb interaction between electrons and holes impedes carrier separation, thus hindering efficient utilization of photo-energy. Herein, porphyrinic metal-organic frameworks with (FeNi)O(COO) clusters are used as photocathodes to accelerate exciton dissociation into charge carriers for light-assisted Li-O batteries.

Regulating Ion-Dipole Interactions in Weakly Solvating Electrolyte towards Ultra-Low Temperature Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) are recognized as promising energy storage devices. However, they suffer from rapid capacity decay at ultra-low temperatures due to high Na desolvation energy barrier and unstable solid electrolyte interphase (SEI). Herein, a weakly solvating electrolyte (WSE) with decreased ion-dipole interactions is designed for stable sodium storage in hard carbon (HC) anode at ultra-low temperatures.

New Reaction Pathway of Superoxide Disproportionation Induced by a Soluble Catalyst in Li-O Batteries.

Aprotic Li-O battery has attracted considerable interest for high theoretical energy density, however the disproportionation of the intermediate of superoxide (O ) during discharge and charge leads to slow reaction kinetics and large voltage hysteresis. Herein, the chemically stable ruthenium tris(bipyridine) (RB) cations are employed as a soluble catalyst to alternate the pathway of O disproportionation and its kinetics in both the discharge and charge processes. RB captures O dimer and promotes their intramolecular charge transfer, and it decreases the energy barrier of the disproportionation reaction from 7.

Solvation Structure with Enhanced Anionic Coordination for Stable Anodes in Lithium-Oxygen Batteries.

Li-O batteries have garnered much attention due to their high theoretical energy density. However, the irreversible lithium plating/stripping on the anode limits their performance, which has been paid little attention. Herein, a solvation-regulated strategy for stable lithium anodes in tetraethylene glycol dimethyl ether (G4) based electrolyte is attempted in Li-O batteries.

Atomic Ruthenium-Riveted Metal-Organic Framework with Tunable d-Band Modulates Oxygen Redox for Lithium-Oxygen Batteries.

Non-aqueous Li-O batteries have aroused considerable attention because of their ultrahigh theoretical energy density, but they are severely hindered by slow cathode reaction kinetics and large overvoltages, which are closely associated with the discharge product of LiO. Herein, hexagonal conductive metal-organic framework nanowire arrays of nickel-hexaiminotriphenylene (Ni-HTP) with quadrilateral Ni-N units are synthesized to incorporate Ru atoms into its skeleton for NiRu-HTP. The atomically dispersed Ru-N sites manifest strong adsorption for the LiO intermediate owing to its tunable d-band center, leading to its high local concentration around NiRu-HTP.

Quenching singlet oxygen via intersystem crossing for a stable Li-O battery.

Aprotic Li-O batteries are a promising energy storage technology, however severe side reactions during cycles lead to their poor rechargeability. Herein, highly reactive singlet oxygen (O) is revealed to generate in both the discharging and charging processes and is deterimental to battery stability. Electron-rich triphenylamine (TPA) is demonstrated as an effective quencher in the electrolyte to mitigate O and its associated parasitic reactions, which has the tertiary amine and phenyl groups to manifest excellent electrochemical stability and chemical reversibility.

Metal-Organic Framework-Based Lithium-Oxygen Batteries.

Rechargeable lithium-oxygen batteries (LOBs) are considered to be the next-generation energy technology owing to their high theoretical energy density. However, the sluggish cathode kinetics and degradation of Li anodes result in large voltage hysteresis and low coulombic efficiency. Various materials have been applied to promote the electrochemical performance of LOBs.

Bio-based carbon materials with multiple functional groups and graphene structure to boost methane production from ethanol anaerobic digestion.

This study evaluated the effects of bio-based carbon materials on methane production by anaerobic digestion. The results showed that biochar and hydrochar can promote cumulative methane yield by 15% to 29%. However, there was no statistical significance (p > 0.

Asymmetric Structure Design of Electrolytes with Flexibility and Lithium Dendrite-Suppression Ability for Solid-State Lithium Batteries.

Solid polymer electrolytes can be used to construct solid-state lithium batteries (SSLBs) using lithium metals as the anode. However, the lifespan and safety problems of SSLBs caused by lithium dendrite growth have hindered their practical application. Here, we have designed and prepared a rigid-flexible asymmetric solid electrolyte (ASE) that is used in building SSLBs.

3D web freestanding RuO-CoO nanowires on Ni foam as highly efficient cathode catalysts for Li-O batteries.

The mechanism of Li-O batteries is based on the reactions of lithium ions and oxygen, which hold a theoretical higher energy density of approximately 3500 W h kg. In order to improve the practical specific capacity and cycling performance of Li-O batteries, a catalytically active mechanically robust air cathode is required. In this work, we synthesized a freestanding catalytic cathode with RuO decorated 3D web CoO nanowires on nickel foam.