Electrochemical BMS Charging Control for Lithium Plating Prevention
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Solution Overview
Problem
Lithium plating on the anodes of lithium ion batteries during charging operations leads to battery degradation, and existing current limits for charging are often overly conservative, resulting in inefficient charging.
Innovation Solution
A battery management system (BMS) utilizing an electrochemical model to dynamically control charging operations by monitoring parameters such as state of charge, temperature, and charging current, and adjusting these parameters to prevent lithium plating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing current limits for charging are applied, then lithium plating is prevented, but charging efficiency is reduced
Solution Approach 1:
The patent implements dynamic current limiting that adjusts charging current based on real-time battery state parameters (temperature, state of charge, aging level). Instead of applying a fixed conservative current limit throughout charging, the system dynamically modifies the current limit to allow higher currents when conditions permit, thereby maintaining lithium plating prevention while improving charging efficiency.
Solution Approach 2:
The system changes multiple parameters simultaneously including temperature monitoring, state of charge thresholds, and current limit values based on battery aging level. By adjusting these parameters dynamically, the system optimizes the balance between preventing lithium plating and maintaining efficient charging operations.
2Duration of action of stationary object
If conservative charging current is used, then battery degradation is reduced, but charging time increases
Solution Approach 1:
The system performs preliminary assessment of battery conditions (temperature, state of charge, aging level) before initiating charging and continuously monitors during charging. This preliminary and ongoing assessment allows the system to proactively adjust current limits to prevent degradation while minimizing charging time, rather than relying on fixed conservative limits.
Solution Approach 2:
The patent implements a feedback mechanism that continuously monitors battery parameters during charging and adjusts the current limit accordingly. This closed-loop control ensures that charging current is optimized in real-time to balance battery lifespan preservation with reduced charging time, preventing both overcharging and unnecessary current restrictions.
3Productivity
If dynamic current limiting based on multiple parameters is implemented, then charging efficiency is improved, but system complexity increases
Solution Approach 1:
The patent segments the control system into distinct functional modules: temperature monitoring module, state of charge calculation module, aging level assessment module, and current limit determination module. Each module handles a specific aspect of the dynamic current limiting process, making the overall complex system more manageable and easier to implement while achieving improved charging efficiency.
Data Source
AI summary
A battery system includes a lithium ion battery configured to couple to an electrical system, and a battery management system configured to electrically couple to the lithium ion battery and to control one or more recharge parameters of the lithium ion battery. The battery management system is programmed with an electrochemical model, and the battery management system is configured to monitor parameters of the lithium ion battery, and to control the one or more recharge parameters of the lithium ion battery based on the electrochemical model and the one or more monitored parameters. The electrochemical model determines lithium plating reaction kinetics at an anode of the lithium ion battery, determines a quantity of plated lithium at the anode of the lithium ion battery, or both, and indicates a relationship between the one or more monitored parameters and the lithium plating reaction kinetics, the quantity of plated lithium, or both.