US 12,126,006 B2
Positive electrode active material composite body
Tomofumi Yokoyama, Matsumoto (JP); Hitoshi Yamamoto, Chino (JP); Tsutomu Teraoka, Matsumoto (JP); and Naoyuki Toyoda, Suwa (JP)
Assigned to SEIKO EPSON CORPORATION, (JP)
Filed by Seiko Epson Corporation, Tokyo (JP)
Filed on Nov. 4, 2020, as Appl. No. 17/088,895.
Claims priority of application No. 2019-201088 (JP), filed on Nov. 5, 2019.
Prior Publication US 2021/0135191 A1, May 6, 2021
Int. Cl. H01M 4/134 (2010.01); H01M 4/131 (2010.01); H01M 4/525 (2010.01); H01M 10/0525 (2010.01); H01M 4/02 (2006.01)
CPC H01M 4/134 (2013.01) [H01M 4/131 (2013.01); H01M 4/525 (2013.01); H01M 10/0525 (2013.01); H01M 2004/028 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A positive electrode active material composite body, comprising:
a positive electrode active material containing a transition metal element and having a particulate shape; and
an ion conductor provided in contact with a surface of the positive electrode active material, wherein
the ion conductor is constituted by a material containing Li, Zr, and M which is at least one type of element selected from the group consisting of Nb, Sb, and Ta,
the transition metal element is partially diffused in the ion conductor,
an average decrease ratio of a content ratio of the transition metal element until a point where the content ratio of the transition metal element in the ion conductor to be determined by a characteristic X-ray has reached 12% of the content ratio of the transition metal element at an interface between the positive electrode active material and the ion conductor based on a substance amount is 0.5% or more and 6.1% or less per 1 nm thickness from the interface, and
wherein the ion conductor is a garnet-type or garnet-like crystal that is represented by a compositional formula: Li7-xLa3(Zr2-xMx)O12, and that satisfies 0.7≤x≤1.3.