Thermal chain determination method and thermal chain detection system for battery pack

Patent metadata

Field	Value
Publication number	US-12531285-B2
Application number	US-202117629676-A
Country	US
Kind code	B2
Filing date	Apr 14, 2021
Priority date	Apr 14, 2021
Publication date	Jan 20, 2026
Grant date	Jan 20, 2026

Abstract

A battery pack includes cells, a pressure contributing component contributing to a change in pressure in the battery pack, at least one pressure sensor configured to detect the pressure in the battery pack, and at least one voltage sensor configured to detect a voltage of the cells. A thermal chain determination method includes detecting the pressure in the battery pack, detecting the voltage of the cells, determining that the pressure in the battery pack is abnormal when an amount or rate of change is larger than a predetermined value, determining that the voltage of the cells is abnormal when an amount or rate of change in the detected voltage is larger than a predetermined value, or when an absolute value of the voltage of the cells is smaller than a predetermined value, and determining that a thermal chain occurs when both the pressure and the voltage are abnormal.

First claim

The invention claimed is:

1 . A thermal chain detection system comprising:
a battery pack housing a plurality of cells; a gas discharge passage coupling the plurality of cells and an outside of the battery pack, wherein the gas discharge passage is coupled to one of the plurality of cells in the battery pack and is capable of contributing to a change in a pressure in the battery pack during normal operation of the plurality of cells; at least one pressure sensor configured to detect the pressure in the battery pack, wherein only one pressure sensor is provided downstream of a portion of the gas discharge passage where the gas discharge passage is coupled to the one of the plurality of cells; at least one voltage sensor configured to detect a voltage of the plurality of cells; and a display unit configured to notify and warn that a thermal chain has occurred in the battery pack, and a controller configured to:
determine that the pressure in the battery pack is abnormal when an amount of change in the pressure in the battery pack is greater than a predetermined pressure change amount or a rate of change in the pressure in the battery pack is larger than a predetermined pressure change rate;
determine that the voltage of the plurality of cells is abnormal when an amount of change in the voltage of the plurality of cells is greater than a predetermined voltage change amount or a rate of change in the voltage of the plurality of cells is greater than a predetermined voltage change rate or an absolute value of the voltage of the plurality of cells is less than a predetermined voltage; and
cause the display unit to display a thermal chain occurrence notification and warning only when a determination that the pressure in the battery pack is abnormal and a determination that the voltage of the plurality of cells is abnormal are made together,
wherein the determination that the pressure in the battery pack is abnormal is maintained for a predetermined time even in a case where the amount of change in the pressure in the battery pack becomes equal to or less than the predetermined pressure change amount and the rate of change in the pressure in the battery pack becomes equal to or less than the predetermined pressure change rate after the determination that the pressure in the battery pack is abnormal is made.

2 . The thermal chain detection system according to claim 1 , wherein
the controller includes a battery controller receiving input including the pressure detected by the at least one pressure sensor and the voltage detected by the at least one voltage sensor, and a vehicle controller that determines whether the thermal chain occurs, and the vehicle controller assumes the amount of change in the voltage of the plurality of cells is greater than the predetermined voltage change amount or the rate of change in the voltage of the plurality of cells is greater than the predetermined voltage change rate or the absolute value of the voltage of the plurality of cells is less than the predetermined voltage in any one of cases where the vehicle controller detects an internal short circuit based on the voltage detected by the at least one voltage sensor, where a voltage value detected by the at least one voltage sensor is an invalid value, or where communication between the battery controller and the vehicle controller is poor.

3 . The thermal chain detection system according to claim 1 , wherein
the at least one pressure sensor is provided at a position where the at least one pressure sensor would not be affected by the thermal chain in the battery pack when the thermal chain occurs in the battery pack.

4 . The thermal chain detection system according to claim 1 , wherein
the controller includes a battery controller that receives input including the pressure detected by the at least one pressure sensor and the voltage detected by the at least one voltage sensor, and a vehicle controller that determines whether the thermal chain occurs, the at least one voltage sensor is provided in the battery pack, and the vehicle controller is provided outside the battery pack.

5 . The thermal chain detection system according to claim 1 , wherein
the battery pack is an open-type battery pack, and the at least one voltage sensor and the controller are provided in the battery pack.

6 . A thermal chain detection system, comprising:
a battery pack comprising a plurality of cells, a gas discharge passage coupling at least one of the plurality of cells with an outside of the battery pack, at least one pressure sensor configured to detect pressure in the battery pack, and at least one voltage sensor configured to detect a voltage of at least one cell of the plurality of cells, wherein the gas discharge passage is capable of contributing to a change in pressure in the battery pack during normal operation of the battery pack, and wherein the at least one pressure sensor is provided downstream of where the gas discharge passage is coupled to the at least one of the plurality of cells; a display unit configured to display at least one of a warning or a notification; and a controller configured to:
based on input from the at least one pressure sensor and the at least one voltage sensor, determine whether a change in the pressure within the battery pack is related to an occurrence of a thermal chain; and
in response to determining that the change in pressure in the battery pack is due to the thermal chain, cause the display unit to display the at least one of the warning or the notification that the thermal chain has occurred in the battery pack.

7 . The thermal chain detection system according to claim 6 , wherein the determination that the voltage of the at least one cell of the plurality of cells is abnormal is made in a case where an amount of change or a rate of change in the voltage of the at least one cell of the plurality of cells is larger than a predetermined value or in a case where an absolute value of the voltage of the at least one cell of the plurality of cells is less than a predetermined value.

8 . The thermal chain detection system according to claim 6 , wherein a downstream portion of the gas discharge passage is closed by an air-permeable membrane that adjusts pressure in the gas discharge passage.

9 . The thermal chain detection system according to claim 6 , wherein a determination is made that no thermal chain occurs in response to a determination that the pressure in the battery pack is abnormal and a determination that the voltage of the at least one cell of the plurality of cells is normal.

10 . The thermal chain detection system according to claim 9 , wherein the determination that the pressure in the battery pack is abnormal is made in a case where an amount of change or a rate of change in the pressure in the battery pack is larger than a predetermined value.

11 . A thermal chain detection system, comprising:
a battery pack comprising a plurality of cells, a gas discharge passage coupling at least one of the plurality of cells with an outside of the battery pack, at least one pressure sensor configured to detect pressure in the battery pack, and at least one voltage sensor configured to detect a voltage of at least one cell of the plurality of cells, wherein the gas discharge passage is capable of contributing to a change in pressure in the battery pack during normal operation of the battery pack, and wherein the at least one pressure sensor is provided downstream of where the gas discharge passage is coupled to the at least one of the plurality of cells; a display unit configured to display at least one of a warning or a notification; and a controller configured to

Assignees

• Nissan Motor

Inventors

• Taguchi Hiromoto
• Matsuyama Ayuka
• Kasedo Kohei
• Yang Qiye
• Zhou Xubin
• Kobayashi Tomokazu
• Miyake Ko
• Ogawa Hiroshi

Classifications

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• G01L19/0092

  Pressure sensor associated with other sensors, e.g. for measuring acceleration or temperature (G01L9/025, G01L9/045, G01L9/065, G01L9/085, G01L9/105, G01L9/125, G01L19/02, G01L19/04 take precedence; measuring two or more variable G01D21/02; temperature sensors with pressure compensation G01K1/26) · CPC title

• B60L2240/547

  Voltage · CPC title

• B60L2240/545

  Temperature · CPC title

• B60L3/0046

  relating to electric energy storage systems, e.g. batteries or capacitors · CPC title