US 12,265,133 B2
Method for inspecting nonaqueous electrolyte rechargeable battery
Shusaku Goto, Hamamatsu (JP); and Hiroaki Ikeda, Tokyo (JP)
Assigned to TOYOTA BATTERY CO., LTD., Kosai (JP); TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP); and PRIME PLANET ENERGY & SOLUTIONS, INC., Tokyo (JP)
Filed by PRIMEARTH EV ENERGY CO., LTD., Kosai (JP); TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP); and PRIME PLANET ENERGY & SOLUTIONS, INC., Tokyo (JP)
Filed on Nov. 30, 2022, as Appl. No. 18/072,563.
Claims priority of application No. 2021-197140 (JP), filed on Dec. 3, 2021.
Prior Publication US 2023/0176134 A1, Jun. 8, 2023
Int. Cl. G01R 31/3835 (2019.01); G01R 19/165 (2006.01); G01R 31/374 (2019.01); G01R 31/385 (2019.01); G01R 31/392 (2019.01)
CPC G01R 31/3835 (2019.01) [G01R 19/16542 (2013.01); G01R 31/374 (2019.01); G01R 31/3865 (2019.01); G01R 31/385 (2019.01); G01R 31/392 (2019.01)] 4 Claims
OG exemplary drawing
 
1. A method for inspecting a nonaqueous electrolyte rechargeable battery that includes an electrode body, a nonaqueous electrolyte, and a battery case accommodating the electrode body and the nonaqueous electrolyte, the method comprising:
a high-temperature aging step of storing, under a high-temperature environment, the nonaqueous electrolyte rechargeable battery after being charged;
a cooling step of cooling the nonaqueous electrolyte rechargeable battery stored under the high-temperature environment in the high-temperature aging step; and
an inspecting step of inspecting, upon completion of the cooling step, whether the nonaqueous electrolyte rechargeable battery is normal based on a voltage drop value per unit time in the nonaqueous electrolyte rechargeable battery, wherein
the inspecting step includes a first period after the cooling step ends and a second period after the first period ends,
variations in the voltage drop value per unit time in the nonaqueous electrolyte rechargeable battery are smaller in the second period than in the first period,
the inspecting step inspects whether the nonaqueous electrolyte rechargeable battery is normal in a state where the electrode body is directly or indirectly pressurized and restrained in a thickness direction,
the cooling step cools the nonaqueous electrolyte rechargeable battery in a state where the electrode body is directly or indirectly pressurized and restrained in the thickness direction with a smaller pressure than a pressure in the inspecting step or in a state where the electrode body is not restrained, and
the inspecting step includes:
a first measuring step of measuring a voltage value of the nonaqueous electrolyte rechargeable battery in the second period;
a third measuring step of measuring, in the second period, the voltage value of the nonaqueous electrolyte rechargeable battery when a time shorter than a specified time has passed after the first measuring step was performed;
a first determining step of determining that the nonaqueous electrolyte rechargeable battery is normal when the voltage drop value per unit time based on the voltage value measured in the first measuring step and the voltage value measured in the third measuring step is less than or equal to a threshold value;
a second measuring step of measuring, in the second period, in a case where the first determining step determines that the nonaqueous electrolyte rechargeable battery is not normal, the voltage value of the nonaqueous electrolyte rechargeable battery when the specified time has passed after the first measuring step was performed; and
a second determining step of determining that the nonaqueous electrolyte rechargeable battery is normal when the voltage drop value per unit time based on the voltage value measured in the first measuring step and the voltage value measured in the second measuring step is less than or equal to fall the threshold value.