System and method for charge protection of a lithium-ion battery
AssigneeToyota Motor Europe
InventorsYuya Ishihara, Yuki Katoh
Life of this patent
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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.
Claims6
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 d2T/dt2 from the temperature history data,
- comparing a negative of the value of the second order differential to a constant C0 that delineates a normal range for −d2T/dt2, and
- when the value of the second order differential is greater than or equal to C0, determining whether a value of a first order differential dT/dt is greater than 0 as the indication of sulfur sublimation.
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 d2T/dt2 from the temperature history data,
- compare a negative of the value of the second order differential to a constant C0 delineating a normal range for −d2T/dt2, and
- when the value of the second order differential is greater than or equal to C0, further determine whether a value of a first order differential dT/dt is greater than 0 as the indication of the sulfur sublimation.
Dependencies are inferred from the claim text.