The electrochemical cell stack includes an electrochemical cell disposed between a first separator and a second separator. The electrochemical cell includes an anode, a cathode, and a solid electrolyte layer disposed between the anode and the cathode. The solid electrolyte layer, containing a zirconia-based material as a main component, has a downstream part and an upstream part. The downstream part is positioned on a downstream side in a flow direction of a fuel gas in a fuel flow passage between the anode and the first separator. The upstream part is positioned on an upstream side in the flow direction. The downstream part includes a first region within 3 μm from an anode side surface, and a second region between the first region and the cathode. An intensity ratio of tetragonal zirconia to cubic zirconia in a Raman spectrum of the first region is greater than that of the second region.

An electrochemical cell stack includes an electrochemical cell disposed between a first separator and a second separator. The electrochemical cell includes an anode, a cathode, and a solid electrolyte layer disposed between the anode and the cathode. The solid electrolyte layer, containing a zirconia-based material as a main component, has an upstream part and a downstream part. The upstream part is positioned on the upstream side in the flow direction of a fuel gas in the fuel flow passage between the anode and the first separator. The downstream part is positioned on the downstream side in the flow direction. The upstream part includes a first region within 3 μm from the anode side surface, and a second region provided on the first region. An intensity ratio of tetragonal zirconia to cubic zirconia in a Raman spectrum of the first region is greater than that of the second region.

Provided is a non-aqueous electrolyte secondary battery capable of reliably operating an electricity shut-off mechanism at overcharging without deteriorating battery performance. The non-aqueous electrolyte secondary battery (1) includes, in a container (2): a positive electrode (41); in-container positive electrode terminals (21) and (23); a negative electrode (42); in-container negative electrode terminals (22) and (24); a non-aqueous electrolyte solution; and an electricity shut-off mechanism (68b) capable of shutting off energization with the outside of the container when the internal pressure of the container rises. A solid electrolyte layer that produces gas allowing the electricity shut-off mechanism (68b) to be operated is included in at least one member of a positive electrode mixture layer unformed portion (41b), a negative electrode mixture layer unformed portion (42b), the in-container positive electrode terminals (21) and (23), and the in-container negative electrode terminals (22) and (24).

An electrolyte according to the invention includes a first electrolyte portion, in which one or more types of elements among the elements constituting a crystalline lithium composite metal oxide represented by the compositional formula (1) are substituted with a first metal element having a crystal radius of 78 pm or more, and an amorphous second electrolyte portion, which contains Li and one or more types of second metal elements contained in the first electrolyte portion other than Li.
Li.sub.7(La.sub.3−xNd.sub.x)Zr.sub.2O.sub.12  (1) In the formula, x satisfies the following formula: 0.0<x≤0.6.

The invention provides an electrolyte material for a solid oxide fuel cell comprising a perovskite oxide comprising at least one element A selected from the group consisting of Ba and Sr, an element Zr, at least one element M selected from the group consisting of Y and Yb, and oxygen, and also a solid phase method for producing the electrolyte material.

A solid-state battery comprises an anode in electrical contact with an anode current collector, including a first ionically conductive solid electrolyte material having a susceptibility to reduction in a presence of lithium metal such that, upon contact with lithium, the ionically conductive material partially reduces to a mixed ionic and electronic conductor including a partially reduced species, a cathode, and a separator positioned between and in ionic contact with the anode and cathode. The separator is formed of a second ionically conductive solid electrolyte material which is in contact with the first ionically conductive material but not susceptible to reduction in a presence of lithium metal and not soluble for the partially reduced species such that the separator has a susceptibility for migration of lithium ions from the mixed ionic and electronic conductor and impedes propagation or exchange of the partially reduced species from the mixed ionic and electronic conductor.

Solid-state batteries offer improved safety and the high-energy-density capabilities required for next generation demands of electric vehicles. Disclosed is a method for fabricating high-current-density solid-state batteries, and the associated device structures and systems. The method of fabrication includes purifying surfaces of a solid electrolyte, depositing materials to form deposition layers on the surfaces of the solid electrolyte in a vacuum, and forming oxygen-deficient interfaces at the interface of the deposition layers and the solid electrolyte. The methods and associated devices form high-current-density solid-state batteries with stable electrochemical performance over hundreds of electric cycles.

An electrochemical cell includes an electrolyte arranged between a hydrogen electrode and an oxygen electrode. The electrolyte contains a ceria-based material having a fluorite crystal structure and a stabilized zirconia-based material. The electrolyte may include a first electrolyte located on a side close to the hydrogen electrode and containing the ceria-based material. The electrolyte may further include a second electrolyte located on a side close to the oxygen electrode and containing the ceria-based material. The electrolyte may further include a third electrolyte located between the first electrolyte and the second electrolyte and containing the stabilized zirconia-based material.

A component for a lithium battery including a first layer including a lithium garnet having a porosity of 0 percent to less than 25 percent, based on a total volume of the first layer; and a second layer on the first layer and having a porosity of 25 percent to 80 percent, based on a total volume of the second layer, wherein the second layer is on the first layer and the second layer has a composition that is different from a composition of the first layer.

Multilayer electrodes and/or solid electrolytes having an OIPC cover material, and solvent-free methods for preparing the multilayers, as well as solid-state full batteries having the multilayers are disclosed.