High-performance aqueous sodium-ion battery using a hybrid electrolyte with a wide electrochemical stability window.

The practical application of aqueous sodium-ion batteries (ASIBs) is limited by the electrolysis of water, which results in a low working voltage and energy density of ASIBs. Here, a NaClO-based acetonitrile/water hybrid electrolyte (NaClO(HO)AN) is applied to ASIBs for the first time, which effectively extends the electrochemical stability window (ESW) to 3.0 V and reduces the internal resistance of the battery.

Polydopamine-coated graphene nanosheets as efficient electrocatalysts for oxygen reduction reaction.

Polydopamine-modified graphene (G-PDA) materials were synthesized by polymerization of a dopamine monomer on the surface of graphene oxide. X-ray photoelectron spectroscopy (XPS) has confirmed that new N-containing functional groups are formed during the synthesis process, which result in the excellent electrocatalytic activity of the composite towards ORR in terms of onset potential, number of electron transferred and limiting current density. The electrocatalytic activity of the optimized G-PDA sample is better than N-doped graphene and comparable to the commercial 20 wt% Pt/C catalyst.