Device and method for producing composite active material powder using a production device including a rotating body with blades each having a tapered section at an end part thereof on a front side in a rotation/movement direction of the rotating body
A device produces a composite active material powder by coating active material or composite particle surfaces, which are obtained by coating the active material particle surfaces with an oxide-based solid electrolyte, with a sulfide-based solid electrolyte. The device includes: a storage body having a cylindrical inner wall surface, and a rotating body disposed in an internal space surrounded by the storage body inner wall surface, having a rotating shaft aligned with the internal space central axis, and which includes blades. Each blade end part has such a tapered section on a front side in the rotating body rotation/movement direction, that a thickness of the blade gradually tapers toward a blade end side, and each blade end part has such a curved end surface on a back side in the rotating body rotation/movement direction, that the curved end surface faces the storage body inner wall surface and is generally parallel thereto.
1. A method for producing a composite active material powder,
wherein surfaces of active material particles or composite particles, which are obtained by coating the surfaces of the active material particles with an oxide-based solid electrolyte, are coated with a sulfide-based solid electrolyte by preparing a production device, putting the sulfide-based solid electrolyte and any one of the active material particles and the composite particles into a storage body of the production device, and then rotating a rotating body;
wherein the production device comprises:
the storage body which has a cylindrical inner wall surface; and
the rotating body which is disposed in an internal space that is surrounded by the inner wall surface of the storage body, which has a rotating shaft that is aligned with a central axis of the internal space, and which includes a plurality of blades,
wherein each blade has a leading side and a substantially planar trailing side in a rotation/movement direction of the rotating body, and an end part which adjoins the leading side and the substantially planar trailing side, respectively, the end part having a tapered section at the leading side in which the thickness of the blade gradually tapers toward a blade end, and at which blade end, the end part transitions into a curved end surface which directly adjoins the substantially planar trailing side of the blade, and the curved end surface faces the inner wall surface of the storage body and is generally parallel to the inner wall surface of the storage body, and
wherein a width of the curved end surface of the end part of each blade is in a range of 0.1 to 0.7 with respect to the thickness of the blade.
2. The method for producing the composite active material powder according to claim 1 , wherein a width of the curved end surface of the end part of each blade is in a range of 1/6 to 1/2 with respect to the thickness of the blade.
3. The method for producing the composite active material powder according to claim 1 , wherein, in a rotating shaft direction front view of the rotating body, a length of the end part of each blade in a radial direction of the rotating body is 0.5 to 30 mm.
4. The method for producing the composite active material powder according to claim 1 , wherein the width of the curved end surface of the end part of each blade is 0.5 to 30 mm.
5. The method for producing the composite active material powder according to claim 1 , wherein a clearance between the curved end surface of the end part of each blade and the inner wall surface of the storage body is 0.5 to 10 mm.
6. The method for producing the composite active material powder according to claim 1 , wherein, in the rotating shaft direction front view of the rotating body, an inclined angle of the tapered section is 10 to 80° to a tangent line at a point of intersection between an inclined surface of the tapered section and the inner wall surface of the storage body.
7. The method for producing the composite active material powder according to claim 1 , wherein the active material particles are particles which contain at least any one of a cobalt element, a nickel element and a manganese element, and which further contain a lithium element and an oxygen element.