US 12,224,435 B2
Storage battery
Ryosuke Yagi, Yokohama Kanagawa (JP); Yasuhiro Harada, Isehara Kanagawa (JP); Norio Takami, Yokohama Kanagawa (JP); Tetsuya Sasakawa, Yokohama Kanagawa (JP); Norihiro Yoshinaga, Yokohama Kanagawa (JP); and Yuta Kanai, Tokyo (JP)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (JP)
Filed by KABUSHIKI KAISHA TOSHIBA, Tokyo (JP)
Filed on Jan. 20, 2022, as Appl. No. 17/580,529.
Application 17/580,529 is a continuation of application No. PCT/JP2021/003748, filed on Feb. 2, 2021.
Claims priority of application No. 2020-125399 (JP), filed on Jul. 22, 2020.
Prior Publication US 2022/0149363 A1, May 12, 2022
Int. Cl. H01M 4/485 (2010.01); H01M 4/02 (2006.01); H01M 4/583 (2010.01)
CPC H01M 4/485 (2013.01) [H01M 4/583 (2013.01); H01M 2004/027 (2013.01)] 2 Claims
OG exemplary drawing
 
1. A storage battery comprising:
a first battery module including a plurality of first cells connected in series, each of the plurality of first cells containing titanium composite oxide as a negative electrode active material; and
a second battery module including a plurality of second cells connected in series, each of the plurality of second cells containing a carbonaceous material as a negative electrode active material, the second battery module being connected in parallel with the first battery module,
wherein
a voltage of the storage battery is changeable between a lower limit voltage value and an upper limit voltage value,
at the lower limit voltage value of the storage battery, an SOC of the second battery module is lower than an SOC of the first battery module, and a resistance of the second battery module is higher than a resistance of the first battery module,
at the upper limit voltage value of the storage battery, the SOC of the second battery module is higher than the SOC of the first battery module, and the resistance of the second battery module is higher than the resistance of the first battery module, and
the first battery module and the second battery module satisfy the following formulas (1) and (2):

OG Complex Work Unit Math
wherein Va1 (X) represents an open circuit voltage at SOC=X % of each of the plurality of first cells, Va2 (X) represents an open circuit voltage at SOC=X % of each of the plurality of second cells, M represents the number of the plurality of first cells connected in series in the first battery module, and N represents the number of the plurality of second cells connected in series in the second battery module.