Battery Discharge Control via Slope Analysis
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Solution Overview
Problem
Silicon-based active materials in batteries experience volume expansion and dead active material generation during charging, leading to reduced battery life due to decreased contact between active materials, which limits their cycle life and efficiency.
Innovation Solution
A device and method for controlling discharge by generating a discharge profile, calculating its slope, and terminating the discharge when the slope meets specific criteria, thereby reducing the generation of dead active material and enhancing battery life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a silicon-based active material is used as an anode cell material to increase storage capacity, then the battery energy density is improved, but volume expansion occurs upon charging and dead active material is generated during discharge, reducing battery life
Solution Approach 1:
The patent applies preliminary action by determining a specific discharge termination voltage range (3.0V to 3.3V) before full discharge occurs. This pre-established termination criterion prevents the harmful effects of complete discharge on silicon-based anodes, including volume expansion and dead active material generation, thereby extending battery life while maintaining high storage capacity
Solution Approach 2:
The patent changes the discharge termination parameter from the conventional fixed voltage (typically 3.0V) to a flexible voltage range (3.0V to 3.3V). This parameter change allows optimization of discharge termination to prevent silicon-based anode degradation while maintaining high storage capacity, resolving the contradiction between capacity and battery life
2Device complexity
If discharge is terminated at a fixed voltage to simplify control, then the device complexity is reduced, but dead active material is generated and battery life is reduced
Solution Approach 1:
The patent changes the discharge termination parameter from a single fixed voltage value to a flexible voltage range (3.0V to 3.3V). This parameter modification maintains simple control logic while preventing dead active material generation, thereby extending battery life without significantly increasing device complexity
Solution Approach 2:
The patent enables the battery system to self-regulate discharge termination within the 3.0V to 3.3V range, allowing the system to automatically prevent dead active material generation without requiring complex external control mechanisms, thus maintaining simplicity while improving reliability
Data Source
AI summary
The present disclosure relates to a device and method for controlling discharge by calculating a slope of a discharge profile of a battery having a lithium-based cathode material and a silicon-based anode cell material, counting a frequency the slope is equal to or smaller than a preset slope value and adjusting a final discharge voltage in response to the counted frequency being above a predetermined frequency.