US 11,955,642 B2
Electrode, secondary battery, battery pack, and vehicle
Mitsuru Ishibashi, Kanagawa (JP); Wen Zhang, Sagamihara Kanagawa (JP); Kazuomi Yoshima, Kanagawa (JP); Keigo Hoshina, Kanagawa (JP); and Norio Takami, Kanagawa (JP)
Assigned to KABUSHIKI KAISHA TOSHIBA, Tokyo (JP)
Filed by KABUSHIKI KAISHA TOSHIBA, Tokyo (JP)
Filed on Aug. 31, 2020, as Appl. No. 17/007,116.
Claims priority of application No. 2020-050443 (JP), filed on Mar. 23, 2020.
Prior Publication US 2021/0296653 A1, Sep. 23, 2021
Int. Cl. H01M 4/66 (2006.01); H01M 4/02 (2006.01); H01M 4/131 (2010.01); H01M 4/133 (2010.01); H01M 4/134 (2010.01); H01M 4/36 (2006.01); H01M 10/0525 (2010.01); H01M 50/20 (2021.01)
CPC H01M 4/662 (2013.01) [H01M 4/131 (2013.01); H01M 4/133 (2013.01); H01M 4/134 (2013.01); H01M 4/366 (2013.01); H01M 10/0525 (2013.01); H01M 50/20 (2021.01); H01M 2004/021 (2013.01); H01M 2004/027 (2013.01); H01M 2004/028 (2013.01); H01M 2220/20 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An electrode comprising:
a current collector; and
an active material-containing layer supported on the current collector and comprising an active material comprising niobium-titanium composite oxide, a conductive agent, cellulose fiber, a binder, first agglomerates, and second agglomerates, and the conductive agent comprising carbon fiber, wherein:
the active material-containing layer comprises a first surface brought into contact with the current collector, and a second surface which is a reverse face of the first surface; and
400/mm2 to 2000/mm2 of the first agglomerates are present on the second surface, the first agglomerates comprises the carbon fiber and the cellulose fiber, do not comprise the active material, and have a longest diameter of 5 μm or more and a shortest diameter of 1 μm or more,
wherein 4500/mm2 or more of the second agglomerates are present on the first surface; and the second agglomerates comprise the carbon fiber and the cellulose fiber, do not comprise the active material, and have a longest diameter of 2 μm or more and a shortest diameter of 1 μm or more, and
wherein the binder is at least one selected from the group consisting of styrene-butadiene rubber, styrene-acrylate resins, acrylic resins, urethane resins, polytetrafluoroethylene, fluororubber, polyimide resin, core-shell binder, and carboxymethyl cellulose.