The two-electron oxygen reduction reaction in acid is highly attractive to produce H₂O₂, a commodity chemical vital in various industry and household scenarios, which is still hindered by the sluggish reaction kinetics. Herein, both density function theory calculation and in-situ characterization demonstrate that in dual-atom CoIn catalyst, O-affinitive In atom triggers the favorable and stable adsorption of hydroxyl, which effectively optimizes the adsorption of OOH on neighboring Co. As a result, the oxygen reduction on Co atoms shifts to two-electron pathway for efficient H₂O₂ production in acid. The H₂O₂ partial current density reaches 1.92 mA cm⁻² at 0.65 V in the rotating ring-disk electrode test, while the H₂O₂ production rate is as high as 9.68 mol g⁻¹ h⁻¹ in the three-phase flow cell. Additionally, the CoIn-N-C presents excellent stability during the long-term operation, verifying the practicability of the CoIn-N-C catalyst. This work provides inspiring insights into the rational design of active catalysts for H₂O₂ production and other catalytic systems.

A nanosized anode material for lithium ion batteries with silicon as core and amorphous carbon as shell was synthesized by dispersing nanosized silicon in polyvinylidene fluoride solution and a subsequent pyrolysis process. The amorphous nature of the carbon in the composite was detected by X-ray diffraction and Raman spectroscopy. The core/shell structure was further identified by transmission electron microscopy. High reversible capacity and acceptable rate capability were exhibited compared with pristine silicon. The reversible capacity of the silicon@carbon nanocomposite at 50 mA g⁻¹ after 30 cycles is 1290 mAh g⁻¹ with a capacity retention of 97%. A stable reversible capacity of 450 mAh g⁻¹ was delivered even at 1000 mA g⁻¹. These improvements are attributed to the amorphous carbon shell, which suppresses the agglomeration of nanosized silicon, reduces the cell impedance, buffers the volume changes and stabilizes the electrode structure during charge/discharge cycles.

Succinonitrile (SN)-based electrolytes are attractive due to their considerable ionic conductivity and high oxidative stability. However, the spontaneous chemical side-reactions between SN and Li-metal restrict the extensive applications of such electrolytes in next-generation advanced Li-metal batteries. Herein, we report a novel SN-based electrolyte SN–DLi–FEC which combines the dual-salt (lithium bis(trifluoromethane sulfonimide) (LiTFSI) and lithium difluoro(oxalato)borate (LiODFB)) and the fluoroethylene carbonate (FEC) additive. Compared with other SN-based electrolytes such as SN–SLi–FEC (single salt combined with FEC), SN–DLi–FEC can form a more stable and durable organic–inorganic composite SEI film rich in the B–F bond and LiF on the surface of the Li-metal anode. As a result, interfacial compatibility of the SN-based electrolytes and the Li-metal anode can be significantly enhanced. Moreover, SN–DLi–FEC shows high oxidation resistance, high ionic conductivity and good thermal stability. The LiCoO₂ (LCO)/Li battery equipped with SN–DLi–FEC exhibits excellent electrochemical performances at room temperature (RT) and high temperature, and high thermal safety. The novel SN-based electrolyte prepared in this work could be a promising candidate providing better reliability and safety for the development of Li-metal batteries.