All-solid-state Battery Overcharge Detection via Dual Pressure Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
All-solid-state secondary battery systems face challenges in accurately detecting overcharge states due to minimal gas production from solid electrolyte decomposition, leading to false judgments from contact pressure sensors caused by expansion of constraining jigs and active material layers due to aging.
Innovation Solution
Incorporating both contact pressure sensors and gas pressure sensors within the battery system, with the control device stopping charging only when both sensors detect changes exceeding threshold values, to accurately determine overcharge states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contact pressure sensors are used to detect overcharge states in all-solid-state batteries, then overcharge detection is enabled, but false positives occur due to expansion of constraining jigs and active material layers during aging
Solution Approach 1:
The detection function is segmented into two independent sensor systems: contact pressure sensors and gas pressure sensors. Each sensor type monitors a different physical phenomenon, allowing the system to distinguish between genuine overcharge conditions (which produce both contact pressure changes and gas pressure changes) and false conditions (which produce only contact pressure changes due to aging expansion).
Solution Approach 2:
Gas pressure sensors serve as an intermediary verification mechanism. Since gas production from solid electrolyte decomposition is a specific indicator of overcharge, the gas pressure sensor acts as a mediator to confirm whether contact pressure changes are caused by overcharge or by other factors such as aging expansion.
2Reliability
If gas pressure sensors are used to detect overcharge states in all-solid-state batteries, then overcharge detection is enabled, but the method fails due to minimal gas production from solid electrolyte decomposition
Solution Approach 1:
The patent merges two detection methods into a unified overcharge detection system. By combining contact pressure sensor data with gas pressure sensor data, the system compensates for the weakness of each individual method: the contact pressure sensor's false positives are eliminated by gas pressure verification, while the gas pressure sensor's insufficient sensitivity is enhanced by contact pressure correlation.
Solution Approach 2:
The system monitors changes in multiple parameters simultaneously (contact pressure and gas pressure) rather than relying on a single parameter. By establishing threshold values for both parameters and requiring both to exceed their thresholds for overcharge confirmation, the system achieves reliable detection despite the small magnitude of gas pressure changes from solid electrolyte decomposition.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables precise detection of overcharge states, reducing false positives and ensuring safe battery operation by combining contact and gas pressure data.
Implementation Method 1
one or more contact pressure sensors provided at least either between an outermost layer surface of the stacked battery and the outer package, or in the inside of the stacked battery
Implementation Method 2
one or more gas pressure sensors provided in a space inside the outer package
Implementation Method 3
when the battery enters into an overcharge state, the solid electrolyte is decomposed to produce a small amount of gas
Data Source
AI summary
An all-solid-state secondary battery system comprising: a sealed battery having formed by housing, in an outer package, a stacked battery; a jig adapted to constrain the sealed battery in the stacking direction; one or more contact pressure sensors provided at least either between an outermost layer surface of the stacked battery and the outer package or in the inside of the stacked battery; one or more gas pressure sensors provided in a space inside the outer package; and a control device adapted to stop charging by judging as an overcharge state only when the change in contact pressure sensed by at least one of the contact pressure sensors is equal to or more than a threshold value, and the change in gas pressure sensed by at least one of the gas pressure sensors is equal to or more than the threshold value.