A Four-Electron Sulfur Electrode Hosting a Cu /Cu Redox Charge Carrier.

The elemental sulfur electrode with Cu as the charge carrier gives a four-electron sulfur electrode reaction through the sequential conversion of S↔CuS↔Cu S. The Cu-S redox-ion electrode delivers a high specific capacity of 3044 mAh g based on the sulfur mass or 609 mAh g based on the mass of Cu S, the completely discharged product, and displays an unprecedently high potential of sulfur/metal sulfide reduction at 0.5 V vs.

Reverse Dual-Ion Battery via a ZnCl Water-in-Salt Electrolyte.

Dual-ion batteries are known for anion storage in the cathode coupled to cation incorporation in the anode. We flip the sequence of the anion/cation-storage chemistries of the anode and the cathode in dual-ion batteries (DIBs) by allowing the anode to take in anions and a cation-deficient cathode to host cations, thus operating as a reverse dual-ion battery (RDIB). The anion-insertion anode is a nanocomposite having ferrocene encapsulated inside a microporous carbon, and the cathode is a Zn-insertion Prussian blue, Zn[Fe(CN)].