Provided is an air electrode/separator assembly including: a hydroxide ion conductive dense separator; an interface layer containing a hydroxide ion conductive material and an electron conductive material and covering one side of the hydroxide ion conductive dense separator; and an air electrode layer provided on the interface layer and including an outermost catalyst layer composed of a porous current collector and a layered double hydroxide (LDH) covering a surface thereof. The outermost catalyst layer has a porosity of 60% or more.

Systems and methods of the various embodiments may provide low cost bifunctional air electrodes. Various embodiments may provide a bifunctional air electrode, including a metal substrate and particles of metal and/or metal oxide catalyst and/or metal nitride catalyst coated on the metal substrate. Various embodiments may provide a bifunctional air electrode, including a first portion configured to engage an oxygen reduction reaction (ORR) in a discharge mode and a second portion configured to engage an oxygen evolution reaction (OER) in a charge mode. Various embodiments may provide a method for making an air electrode including coating a metal substrate with particles of metal and/or metal oxide catalyst and/or metal nitride catalyst. Various embodiments may provide batteries including air electrodes.

Bipolar electrodes comprising a carbon felt loaded with a polymer material and a nanocarbon material are described herein. The bipolar electrodes are useful in electrochemical cells. In particular, the loaded carbon felt can be used in bipolar electrodes of zinc-halide electrolyte batteries. Processes for manufacturing the loaded carbon felt are also described, involving contacting (e.g., dipping) a carbon felt in a mixture of solvent, polymer material and nanocarbon material.

A redox flow battery where the negative electrode uses carbon dioxide based redox couples. The negative electrode contains a bifunctional catalyst that allows for the reduction of carbon dioxide to carbonaceous species (e.g., formic acid, oxalic acid or their salts) in the battery charge (i.e., energy storage) mode, and for the oxidation of the above-mentioned carbonaceous species in the battery discharge (i.e., energy generation) mode. The positive electrode of the battery can utilize a variety of redox couples including but not restricted to bromine-bromide, chlorine-chloride, vanadium (IV)-vanadium (V), chromium (III)-dichromate (VII), cerium (III)-cerium (IV), oxygen-water (or hydroxide).

In general, the present disclosure is directed to methods to produce stable oxygen electrodes for use in energy storage applications such as fuel cells. Aspects of the disclosure can provide improved stability, especially for oxygen electrodes including strontium, which can broaden applications and reduce costs to improve economic feasibility. Embodiments of the disclosure can include methods for producing oxygen electrodes, compositions of stabilizing coatings that can be applied to electrodes to yield a more stable oxygen electrode, and fuel cells incorporating oxygen electrodes produced according to the disclosure. In particular, the disclosure is directed to a finding that a conformal coating can be achieved by calcining a composition including a strontium salt, a cobalt salt, and a tantalum compound on a base electrode, the base electrode having an elemental composition including strontium.

An electrochemical cell includes a bifunctional air cathode, an anode, and a ceramic electrolyte separator disposed substantially between the bifunctional air cathode and the anode. The anode includes a solid metal and an electrolyte configured to transition to a liquid phase in an operating temperature range. The electrolyte includes at least one of an alkali oxide, boron oxide, a carbonate, a phosphate, and a group III-X transition metal oxide.

Described are aqueous rechargeable hydrogen batteries operating in the full pH range (e.g., pH: 1 to 15) with potential for electrical grid storage. The pH-universal hydrogen batteries operate with different redox chemistry on the cathodes and reversible hydrogen evolution/oxidation reactions (HER/HOR) on the anode. The reactions can be catalyzed by a highly active ruthenium-based electrocatalyst. The ruthenium-based catalysts exhibit comparable specific activity and superior long-term stability of HER/HOR to that of state-of-the-art Pt/C electrocatalyst in the full pH range. New chemistries for aqueous rechargeable hydrogen batteries are also provided.

An air electrode has a plurality of carbon nanotubes and a plurality of layered double hydroxide particles. The plurality of layered double hydroxide particles is supported on the plurality of carbon nanotubes.

Disclosed are a positive electrode for lithium air batteries with excellent stability, a method of manufacturing the same, and a lithium air battery including the same, and a lithium air battery with improved stability by including the positive electrode. The positive electrode may include a conductive material and an ionic liquid such that the process of manufacturing the lithium air battery may be simplified, and the stability of the lithium air battery may be further improved as the result of inhibition of side reactions.

Disclosed is an electrode for lithium-air batteries without using a binder and a carbon additive and a method of manufacturing the same, and more specifically, provided is a nanofiber network-based current collector-catalyst monolithic porous air electrode which has an improved specific surface area and high air permeability as the energy density per weight is increased and the diameter, porosity, and thickness of the nanofibers are controlled by utilizing a significantly light polymer and carbon based material.