System and method for charge protection of a lithium-ion battery

Patent metadata

Field	Value
Publication number	US-10950901-B2
Application number	US-201716315057-A
Country	US
Kind code	B2
Filing date	Mar 31, 2017
Priority date	Mar 31, 2017
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

A method for controlling a charge process of a solid-state battery having a sulfur-based positive electrode is provided. The method includes monitoring and storing a temperature of the solid-state battery and a predetermined interval, when the temperature exceeds a threshold temperature, monitoring the temperature of the solid-state battery and/or processing the stored temperature data of the solid-state battery, for an indication of sulfur sublimation, and terminating a flow of charge current upon detection of the indication of sulfur sublimation.

First claim

The invention claimed is:

1. A method for controlling a charge process of a solid-state battery having a sulfur-based positive electrode, the method comprising:
continuously monitoring and storing a temperature of the solid-state battery at a predetermined interval to obtain temperature history data;
when, during the continuous monitoring, a monitored temperature exceeds a predetermined threshold temperature, processing the temperature history data for an indication of sulfur sublimation; and
terminating a flow of charge current of the solid-state battery upon detection of the indication of sulfur sublimation,
wherein the predetermined threshold temperature is 90 degrees C.,
wherein the monitoring, storing, and processing are performed by a controller of a battery charger,
wherein the processing comprises:
determining a value of a second order differential of a relationship between temperature over time d 2 T/dt 2 from the temperature history data,
comparing a negative of the value of the second order differential to a constant C 0 that delineates a normal range for −d 2 T/dt 2 , and
when the value of the second order differential is greater than or equal to C 0 , determining whether a value of a first order differential dT/dt is greater than 0 as the indication of sulfur sublimation.

2. The method according to claim 1 , wherein the monitoring is performed by a temperature sensor.

3. The method according to claim 1 , wherein the constant C 0 is determined prior to the monitoring.

4. The method according to claim 1 , wherein the constant C 0 is determined experimentally for each battery.

5. A battery charger for a solid state battery having a sulfur-based positive electrode, the battery charger comprising:
a current providing section configured to provide current to the solid-state battery;
a monitoring section configured to continuously monitor and record a temperature of the solid-state battery at a predetermined interval to obtain temperature history data; and
a controller configured to:
when, during the continuous monitoring, a monitored temperature of the solid-state battery exceeds a predetermined threshold temperature, processing the temperature history data for an indication of sulfur sublimation; and
to terminate a flow of current to the solid-state battery when an indication of sulfur sublimation is identified,
wherein the predetermined threshold temperature is 90 degrees C.,
wherein, to process the temperature history for the indication of sulfur sublimation, the controller is further configured to:
determine a value of a second order differential of a relationship between temperature over time d 2 T/dt 2 from the temperature history data,
compare a negative of the value of the second order differential to a constant C 0 delineating a normal range for −d 2 T/dt 2 , and
when the value of the second order differential is greater than or equal to C 0 , further determine whether a value of a first order differential dT/dt is greater than 0 as the indication of the sulfur sublimation.

6. A method, comprising:
connecting a solid-state battery to a battery charger according to claim 5 , and
charging the solid-state battery,
the solid-state battery comprising a sulfur-based positive electrode and a temperature sensor.

Assignees

• Toyota Motor Europe

Inventors

• Ishihara Yuya
• Katoh Yuki

Classifications

• H02J7/977

  of the battery · CPC title

• H01M10/486

  for measuring temperature · CPC title

• H01M4/38 Primary

  of elements or alloys · CPC title

• H01M10/443 Primary

  in response to temperature · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title