Compositions comprised of a tin film, coated by a shell of less than 50 nm thick made of palladium and tin in a molar ratio ranging from 1:4 to 3:1, respectively, are disclosed. Uses of the compositions as an electro-catalyst e.g., in a fuel cell, and particularly for the oxidation of various materials are also disclosed.

A lithium air battery includes: a lithium negative electrode; a positive electrode; and an ion conductive oxygen-blocking film which is disposed on the lithium negative electrode, wherein the ion conductive oxygen-blocking film includes a first polymer including a polyvinyl alcohol or a polyvinyl alcohol blend, and a lithium salt, and wherein the ion conductive oxygen-blocking film has an oxygen transmission rate of about 10 milliliters per square meter per day to about 10,000 milliliters per square meter per day. Also a method of manufacturing a lithium air battery is disclosed.

In accordance with some embodiments of the present disclosure, a method of changing the porosity of the anode is presented. The anode is formed from a composition comprising nickel oxide, a doped ceria, and a stabilized zirconia wherein the weight percentage of the nickel oxide is greater than twenty-five percent. The anode may comprise a single or multiple layers, and may comprise at least one of gadolinia doped ceria (GDC), samaria doped ceria (SDC), or lanthania doped ceria (LDC); and at least one of Yttria stabilized zirconia (YSZ) or scandia stabilized zirconia (ScSZ). The anode may comprise multiple layers. Each layer may comprise a composition having the general formula NiO.sub.x-(doped ceria).sub.y wherein x and y are weight percentages of the composition, and wherein 25<x<100, and 25<y<100, and wherein each successive layer contains more nickel than the preceding layers.

A process for the preparation of a membrane electrode assembly comprising providing, in the following layer order, (I) a green supporting electrode layer comprising a composite of a mixed metal oxide and Ni oxide; (IV) a green mixed metal oxide membrane layer; and (V) a green second electrode layer comprising a composite of a mixed metal oxide and Ni oxide; and sintering all three layers simultaneously.

Provided is a low-cost electrochemical element that includes a high-performance electrode layer. The electrochemical element includes an electrode layer, and the electrode layer contains small particles and large particles. The small particles have a particle diameter of 200 nm or less in the electrode layer, and the large particles have a particle diameter of 500 nm or more in the electrode layer.

An electrode can include a functional layer having an Ln.sub.2MO.sub.4 phase, where Ln is at least one lanthanide optionally doped with a metal and M is at least one 3d transition metal, and a heavily-doped ceria phase. An electrochemical device or a sensor device can include the electrode.

A unit cell includes an air inlet/outlet that is formed on a frame unit rather than being installed in a fuel electrode (anode) to simplify a sealing process, and accordingly, a continuous process using a tape casting technique may be performed. In addition, an electrolyte material that is in contact with an air electrode (cathode) in the frame unit is optimized to improve ion conductivity and a porosity of an upper layer material of the fuel electrode unit is optimized to increase fuel diffusion from a gas channel to an electrolyte layer. In addition, a sealing process performed inside the unit cell or between the unit cells of the stack is stabilized and strongly maintained, and thus a fuel cell using the unit cell and the stack disclosed herein may have excellent economic feasibility and high energy efficiency.

Provided is a catalyst layer for fuel cell which has a high catalytic activity and enables maintaining the high catalytic activity. Disclosed is an electrode catalyst layer for fuel cell including a catalyst containing a catalyst carrier having carbon as a main component and a catalytic metal supported on the catalyst carrier, and a polymer electrolyte having a sulfonic acid group (—SO.sub.3H) as an ion exchange group, in which the catalyst has the R′ (D′/G intensity ratio) of 0.6 or less, which is the ratio of D′ band peak intensity (D′ intensity) measured in the vicinity of 1620 cm.sup.−1 relative to G band peak intensity (G intensity) measured in the vicinity of 1580 cm.sup.−1 by Raman spectroscopy, and has BET specific surface area of 900 m.sup.2/g catalyst carrier or more, and mole number of a sulfonic acid group in the polymer electrolyte relative to weight of the catalyst carrier is 0.7 mmol/g or more and 1.0 mmol/g or less.

Microbial fuel cells capable of generating energy from an organic-based fuel are described. The microbial fuel cells can include an anode component, a cathode component, and a separator component selected to reduce spacing between the anode and the cathode thereby improving performance of the microbial fuel cell. Cathode components including particular components that improve the lifetime, performance, and production of the cathode component at reduced cost also are described, as well as a method of using the microbial fuel cells.

Provided is an electrode catalyst layer excellent in gas transportability by using an electrode catalyst layer for fuel cell comprising a catalyst containing a catalyst carrier and a catalytic metal carried on the catalyst carrier and an electrolyte, wherein the catalyst partially is coated with the electrolyte, and a specific surface area of the catalytic metal which gas can reach without passing through an electrolyte is 50% or more, with respect to the total specific surface area of the catalytic metal.