US 11,811,088 B2
Separator, electrode group, secondary battery, battery pack, vehicle, and stationary power supply
Wataru Uno, Yokohama (JP); Yasuyuki Hotta, Ota (JP); Shinsuke Matsuno, Minato (JP); and Norio Takami, Yokohama (JP)
Assigned to Kabushiki Kaisha Toshiba, Minato-ku (JP)
Filed by Kabushiki Kaisha Toshiba, Minato-ku (JP)
Filed on May 26, 2020, as Appl. No. 16/883,331.
Claims priority of application No. JP2019-170920 (JP), filed on Sep. 19, 2019; and application No. JP2020-086640 (JP), filed on May 18, 2020.
Prior Publication US 2021/0091358 A1, Mar. 25, 2021
Int. Cl. H01M 50/446 (2021.01); H01M 50/449 (2021.01)
CPC H01M 50/446 (2021.01) [H01M 50/449 (2021.01)] 14 Claims
 
1. A secondary battery comprising:
a positive electrode containing a positive electrode active material;
a negative electrode containing a negative electrode active material;
a separator disposed at least between the positive electrode and the negative electrode; and
an aqueous electrolyte, wherein
the separator comprises an inorganic particle layer including an inorganic particle, a polymeric binder and a fiber substance,
the fiber substance is hydrophilic and a mass ratio of the fiber substance with respect to a total mass of the inorganic particle, the polymeric binder and the fiber substance is 0.1 mass % or more and 40 mass % or less, and
a mass ratio of the polymeric binder with respect to a total mass of the inorganic particle, the polymeric binder and the fiber substance is 5 mass % or more and 30 mass % or less.