A flow battery includes: a liquid including a redox mediator; an electrode at least partially immersed in the liquid; a second electrode; an active material at least partially immersed in the liquid, and a circulator that circulates the liquid between the electrode and the active material.

A lithium air battery includes a negative electrode allowing a lithium ion to be occluded in the negative electrode and released from the negative electrode; a positive electrode configured to use oxygen in air as a positive electrode active material; a nonaqueous lithium ion conductor disposed between the negative electrode and the positive electrode; and a copper ion present in at least one selected from the group consisting of the positive electrode and the nonaqueous lithium ion conductor.

Provided are a carbon catalyst, an electrode, and a battery that exhibit excellent activity. A carbon catalyst according to one embodiment of the present invention has a carbon structure in which area ratios of three peaks f.sub.broad, f.sub.middle, and f.sub.narrow obtained by separating a peak in the vicinity of a diffraction angle of 26 in an X-ray diffraction pattern obtained by powder X-ray diffraction satisfy the following conditions (a) to (c): (a) f.sub.broad: 75% or more and 96% or less; (b) f.sub.middle: 3.2% or more and 15% or less; and (c) f.sub.narrow: 0.4% or more and 15% or less.

The present specification relates to a carrier-nanoparticle complex, a catalyst including the same, an electrochemical battery or a fuel cell including the catalyst, and a method for preparing the same.

A flow battery includes: a liquid including a redox mediator; an electrode; a second electrode; an active material; and a circulator that circulates the liquid between the electrode and the active material. The redox mediator includes a tetrathiafulvalene derivative.

A bifunctional catalyst and a preparation method therefor are provided. The bifunctional catalyst is prepared by providing carbon matrix, adding 0.01-10 mol/L platinum containing solution, 0.01-10 mol/L palladium containing solution, 0.01-10 mol/L silver containing solution, and 0.01-15 mol/L sodium citrate trihydrate solution to the carbon matrix for reacting at 20 C. to 80 C. for 0.5 h to 24 h to obtain a mixed solution, and adding reducing agent to the mixed solution for reacting for 0.5 h to 30 h, and centrifuging and drying so as to obtain the bifunctional catalyst.

A battery cell, driven by heat, having a reservoir containing a redox couple electrolyte comprised of paramagnetic and diamagnetic ions. A magnet with a pole, projecting a non-uniform magnetic field unto the electrolyte, the magnetic field having a strong magnetic field area proximal to the magnetic pole and a weak magnetic field area distal to the magnetic pole. A positive electrode is placed in the strong magnetic field area and a negative electrode is placed in the weak magnetic field areas of the electrolyte. Ionic separation occurs as the paramagnetic ions drift to the strong magnetic field area, and the diamagnetic ions are repulsed from the magnetic pole and drift to the weak magnetic field area, causing voltage potential across the positive and negative electrodes. A circuit placed across the positive and negative electrodes of the battery draws electrons from the diamagnetic ions through the negative electrode and the electrical circuit to the positive electrode and into the paramagnetic ions. Paramagnetic ions in the strong field area reduce into converted diamagnetic ions as the paramagnetic ions receive electrons through the positive electrode, the converted diamagnetic ions repelled by the magnetic pole drift to the weak magnetic field area. Additionally, diamagnetic ions proximal to the weak magnetic field area oxidize into converted paramagnetic ions as the diamagnetic ions lose electrons through the negative electrode, the converted paramagnetic ions attracted to the magnetic pole drift to the strong magnetic field area.

A method for synthesis of PtNi nanocages by synthesizing Pt1Ni6 nanoparticles and acid leaching to form PtNi nanocages. The acid leaching removes nickel selectively from the core of the nanoparticle.

An electrode for redox flow batteries is produced using a carbon catalyst for redox flow battery electrodes, the carbon catalyst being a particulate carbon catalyst and consisting of carbonaceous particles having a specific surface area of 800 to 2000 m.sup.2/g and an average particle size of 100 to 1000 nm.

There are provided a metal carbide catalyst complex for a bifunctional zinc-air battery, containing vanadium metal and a different transition metal, and a zinc-air battery system including the same. Because a catalytic reaction region may be increased by a substituted iron ion and a substituted vanadium ion in a metal carbide catalyst complex for a zinc-air battery, high activity for oxygen evolution reaction (OER) performance and high activity for oxygen reduction reaction (ORR) performance may be exhibited.