Abstract: Disclosed is a highly dense aggregate of brittle material particles having an interface at which the particles are bonded to each other and pores between the brittle material particles structuring the highly dense aggregate, where a porosity which is a volume ratio of the pores with respect to the whole of the highly dense aggregate is equal to or less than 20%, and a volume ratio of the pores communicating with an apparent outer surface of the highly dense aggregate with respect to a volume of all of the pores of the highly dense aggregate is equal to or higher than 65%.

Abstract: A flexible all-solid-state battery including a layer of a solid-state polymer electrolyte arranged between a layer of a separator supporting the solid-state polymer electrolyte and a layer including a negative electrode active material is provided. In the flexible all-solid-state battery, the separator may include a woven fabric, a knit, or a non-woven cloth of an inorganic fiber or a polymeric fiber of 1 g/m2 to 70 g/m2 with a thickness in a range from 1 ?m to 100 ?m, an oxide ceramic particle layer including oxide ceramic particles with a particle size from 1 ?m to 20 ?m at a filling rate in a range from 5% to 60%, or a complex of the woven fabric, the knit, or the non-woven cloth and the oxide ceramic particles.

Abstract: Disclosed is a highly dense aggregate of brittle material particles having an interface at which the particles are bonded to each other and pores between the brittle material particles structuring the highly dense aggregate, where a porosity which is a volume ratio of the pores with respect to the whole of the highly dense aggregate is equal to or less than 20%, and a volume ratio of the pores communicating with an apparent outer surface of the highly dense aggregate with respect to a volume of all of the pores of the highly dense aggregate is equal to or higher than 65%.

Abstract: First brittle material particles; and second brittle material particles having smaller size than the first brittle material particles, wherein a void formed between the first brittle material particles is filled with at least one of the second brittle material particles, at a porosity of less than 20%.

Abstract: A method for producing a lithium solid state battery having a solid electrolyte membrane with high Li ion conductivity, in which firm interface bonding is formed on both sides of the membrane, comprising steps of: a membrane-forming step of forming CSE1 not containing a binder, composed of a sulfide solid electrolyte material, on a cathode active material layer by an AD method and ASE1 not containing a binder, composed of a sulfide solid electrolyte material, on an anode active material layer by an AD method, and a pressing step of forming SE1 with the CSE1 and the ASE1 integrated by opposing and pressing the CSE1 and the ASE1, wherein the SE1 such that an interface between the CSE1 and the ASE1 disappeared is formed by improving denseness of the CSE1 and the ASE1 in the pressing step.

Abstract: A method for producing a lithium solid state battery having a solid electrolyte membrane with high Li ion conductivity, in which firm interface bonding is formed on both sides of the membrane, comprising steps of: a membrane-forming step of forming CSE1 not containing a binder, composed of a sulfide solid electrolyte material, on a cathode active material layer by an AD method and ASE1 not containing a binder, composed of a sulfide solid electrolyte material, on an anode active material layer by an AD method, and a pressing step of forming SE1 with the CSE1 and the ASE1 integrated by opposing and pressing the CSE1 and the ASE1, wherein the SE1 such that an interface between the CSE1 and the ASE1 disappeared is formed by improving denseness of the CSE1 and the ASE1 in the pressing step.

Abstract: A method for producing a lithium solid state battery having a solid electrolyte membrane with high Li ion conductivity, in which firm interface bonding is formed on both sides of the membrane, comprising steps of: a membrane-forming step of forming CSE1 not containing a binder, composed of a sulfide solid electrolyte material, on a cathode active material layer by an AD method and ASE1 not containing a binder, composed of a sulfide solid electrolyte material, on an anode active material layer by an AD method, and a pressing step of forming SE1 with the CSE1 and the ASE1 integrated by opposing and pressing the CSE1 and the ASE1, wherein the SE1 such that an interface between the CSE1 and the ASE1 disappeared is formed by improving denseness of the CSE1 and the ASE1 in the pressing step.

Abstract: A method for producing a lithium solid state battery having a solid electrolyte membrane with high Li ion conductivity, in which firm interface bonding is formed on both sides of the membrane, comprising steps of: a membrane-forming step of forming CSE1 not containing a binder, composed of a sulfide solid electrolyte material, on a cathode active material layer by an AD method and ASE1 not containing a binder, composed of a sulfide solid electrolyte material, on an anode active material layer by an AD method, and a pressing step of forming SE1 with the CSE1 and the ASE1 integrated by opposing and pressing the CSE1 and the ASE1, wherein the SE1 such that an interface between the CSE1 and the ASE1 disappeared is formed by improving denseness of the CSE1 and the ASE1 in the pressing step.