A composite electrolyte including a lithium salt; a solid electrolyte wherein the solid electrolyte is a sulfide solid electrolyte, an oxide solid electrolyte, or a combination thereof; and an ionic liquid, wherein a mixture of the ionic liquid and the lithium salt has a dielectric constant of from about 4 to about 12, and an amount of halogen ions eluted from the composite electrolyte after immersion of the solid electrolyte in the ionic liquid for 24 hours is less than about 25 parts per million by weight, based on the total weight of the composite electrolyte, as measured by ion chromatography.

Provided are an all-solid-state battery and a preparation method thereof. The all-solid-state battery includes a positive electrode, a negative electrode, and a solid-state electrolyte located between the positive electrode and the negative electrode. The negative electrode includes a first negative electrode and a second negative electrode. The second negative electrode is located on a side of the first negative electrode. The solid-state electrolyte includes a first solid-state electrolyte and a second solid-state electrolyte. The first solid-state electrolyte is located between the positive electrode and the first negative electrode. The second solid-state electrolyte is located between the positive electrode and the second negative electrode. The roughness of the second solid-state electrolyte is greater than the roughness of the first solid-state electrolyte.

Separator systems for electrochemical systems providing electronic, mechanical and chemical properties useful for applications including electrochemical storage and conversion. Separator systems include structural, physical and electrostatic attributes useful for managing and controlling dendrite formation and for improving the cycle life and rate capability of electrochemical cells including silicon anode based batteries, air cathode based batteries, redox flow batteries, solid electrolyte based systems, fuel cells, flow batteries and semisolid batteries. Separators include multilayer, porous geometries supporting excellent ion transport properties, providing a barrier to prevent dendrite initiated mechanical failure, shorting or thermal runaway, or providing improved electrode conductivity and improved electric field uniformity, as well as composite solid electrolytes with supporting mesh or fiber systems providing solid electrolyte hardness and safety with supporting mesh or fiber toughness and long life required for thin solid electrolytes without fabrication pinholes or operationally created cracks.

A solid-state composite electrode includes active electrode particles, ionically conductive particles, and electrically conductive particles. Each of the ionically conductive particles is at least partially coated with an isolation material that inhibits inter-diffusion of the ionically conductive particles with the active electrode particles. A battery cell includes a first current collector, a solid electrolyte layer, a first solid-state composite electrode having ionically conductive particles coated with an isolation material and positioned between the first current collector and the solid electrolyte layer, a second current collector, and a second electrode positioned between the solid electrolyte layer and the second current collector. A method of forming a solid-state composite electrode includes mixing together active electrode particles and electrically conductive particles with ionically conductive particles that are each at least partially coated with an isolation material. The mixture is formed into a film via tape-casting, and sintered at a temperature greater than 600° C.

Provided is a binder composition for an all-solid-state secondary battery that can produce a slurry composition for an all-solid-state secondary battery having excellent dispersibility and preservation stability and that can cause a solid electrolyte-containing layer to display excellent ion conductivity. The binder composition contains a polymer, ions of a metal belonging to group 1 or group 2 of the periodic table, and a solvent. The solvent includes an organic solvent having a carbon number of 8 or more, and the content of the ions of the metal is not less than 5 mass ppm and not more than 5,000 mass ppm relative to the polymer.

A lithium ion battery is provided which includes an LTO anode; an LNMO cathode; and an electrolyte. At least one of the cathode, anode and electrolyte is Sc doped. The cathode may have a composition within the range of LiNi.sub.0.5Mn.sub.1.495Sc.sub.0.005O.sub.4 to LiNi.sub.0.5Mn.sub.1.25Sc.sub.0.25O.sub.4 or, in some embodiments, LiNi.sub.0.5Mn.sub.1.495Sc.sub.0.005(1−0.01y)X.sub.0.005(0.01y)O.sub.4, wherein 0≤y≤50, and wherein X is one or more metals selected from the group consisting of yttrium, cerium, niobium and zirconium. The anode may have a composition within the range of Li.sub.4Ti.sub.4.99Sc.sub.0.01O.sub.12 to Li.sub.4Ti.sub.4.95Sc.sub.0.05O.sub.12 or, in some embodiments, Li.sub.4Ti.sub.4.995Sc.sub.0.005(1−0.01y)X.sub.0.005(0.01y)O.sub.12 to Li.sub.4Ti.sub.4.995Sc.sub.0.25(1−0.01y)X.sub.0.25(0.01y)O.sub.12, wherein 0≤y≤50, and wherein X is one or more metals selected from the group consisting of yttrium, cerium, niobium and zirconium.

Embodiments relate to a method for fabricating a sintered sodium-ion material. The method involves mixing a parent phase sodium-ion compound with a secondary transient phase to form a powder mixture. The method involves applying pressure and heat above a melting point or boiling point of the secondary transient phase to drive dissolution at particle contacts and subsequent precipitation at newly formed grain boundaries. The method involves generating a sintered sodium-ion material with >90% relative density.

An ionic conductor includes an inorganic oxychloride compound with a chemical composition of (Fe.sub.1-xM.sub.x)O.sub.1-y(OH).sub.yCl.sub.1-x where M is selected from at least one of Mg and Ca, and x is greater than 0 and less than or equal to 0.25, y is greater than or equal to 0 and less than or equal to 0.25. The inorganic oxychloride compound has a thermal decomposition start temperature of about 410° C. and x-ray diffraction peaks (2θ) between about 20.79° and about 22.79°, between about 30.03° and about 32.03°, between about 39.47° and about 41.47°, and between about 76.44° and about 78.44°.

Passivated Li.sub.7La.sub.3Zr.sub.2O.sub.12 (LLZO) particles, tape casting powders and slip compositions including the particles, methods of forming the particles, methods of tape casting using the particles, green tapes including the particles, cast LLZO films formed from the particles, and lithium batteries including the cast LLZO film. A passivated LLZO particle includes an LLZO core, wherein the LLZO is optionally doped with one or more elements. The passivated LLZO particle also includes a shell including H-LLZO, H.sub.3O.sup.+-LLZO, and/or Li.sub.2CO.sub.3.

A method of co-extruding battery components includes forming a first thin film battery component via hot melt extrusion, and forming a second thin film battery component via hot melt extrusion. A surface treatment is applied to a surface region of at least one of the first and second components so that, relative to a remainder of the at least one component, the surface region has at least one of a decreased inter-particle distance, a decreased amount of polymer binder material, and an increased amount of exposed ionically conductive material. The first and second components are fed through a co-extrusion die to form a co-extruded multilayer thin film.