Hydronium-Ion Batteries with Perylenetetracarboxylic Dianhydride Crystals as an Electrode.

We demonstrate for the first time that hydronium ions can be reversibly stored in an electrode of crystalline 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA). PTCDA exhibits a capacity of 85 mAh g at 1 A g after an initial conditioning process. Ex situ X-ray diffraction revealed reversible and significant structure dilation upon reduction of PTCDA in an acidic electrolyte, which can only be ascribed to hydronium-ion intercalation.

High Energy Density Aqueous Electrochemical Capacitors with a KI-KOH Electrolyte.

We report a new electrochemical capacitor with an aqueous KI-KOH electrolyte that exhibits a higher specific energy and power than the state-of-the-art nonaqueous electrochemical capacitors. In addition to electrical double layer capacitance, redox reactions in this device contribute to charge storage at both positive and negative electrodes via a catholyte of IOx-/I- couple and a redox couple of H2O/Had, respectively. Here, we, for the first time, report utilizing IOx-/I- redox couple for the positive electrode, which pins the positive electrode potential to be 0.

Palladium- and gold-nanoparticle-modified porous carbon as a high-power anode for lithium-ion batteries.

Electrode materials: Ultrahigh-power insertion-type anodes are developed by simply decorating Pd nanoparticles on commercially available porous carbon.