公开(公告)号：US20210159501A1

公开(公告)日：2021-05-27

申请号：US17162983

申请日：2021-01-29

Applicant: MURATA MANUFACTURING CO., LTD.

Inventor： Yuichiro HASHIZUME ,  Takeshi HAYASHI

IPC: H01M4/58 ,  H01M10/0525 ,  H01M10/0585 ,  H01M50/204 ,  H01M50/249 ,  H01M10/0567 ,  H01M4/62 ,  H01M4/587

Abstract: A lithium ion secondary battery includes a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte. The positive electrode includes a positive electrode active material layer including a lithium iron phosphate. The positive electrode active material layer has a pore curvature from 50 to 120 as measured by a mercury porosimeter. The negative electrode includes a negative electrode active material layer including graphite. The negative electrode active material layer has a pore curvature from 5 to 30 as measured by the mercury porosimeter.

公开(公告)号：US20250062345A1

公开(公告)日：2025-02-20

申请号：US18938726

申请日：2024-11-06

Applicant: MURATA MANUFACTURING CO., LTD.

Inventor： Yuichiro HASHIZUME

IPC: H01M4/58 ,  H01M4/02 ,  H01M4/36 ,  H01M4/62 ,  H01M10/0525

Abstract: A secondary battery includes: a positive electrode including a positive electrode active material layer; a negative electrode; and an electrolytic solution, in which the positive electrode active material layer includes: a plurality of positive electrode active material particles; and a dispersant. Each of the plurality of positive electrode active material particles includes an olivine type iron-containing phosphate compound, and the dispersant includes a carboxymethylcellulose salt. The plurality of positive electrode active material particles has a volume-based average particle size of 0.6 μm or more, and the dispersant has a weight average molecular weight in terms of polyethylene oxide/polyethylene glycol that satisfies a relationship represented by a formula (1). M≤135106×D+548936  (1) (M represents a weight average molecular weight in terms of polyethylene oxide/polyethylene glycol of a dispersant; and D represents a volume-based average particle size of a plurality of positive electrode active material particles.)