Dynamic Charge Profile for Lithium-Ion Battery Cycle Life
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion battery packs in automotive applications face challenges in accurately estimating remaining capacity and extending cycle life, particularly due to factors like temperature, charge/discharge rates, and usage patterns, which can lead to premature degradation and reduced vehicle range.
Innovation Solution
A management system with a controller that determines an adjustable charge profile for lithium-ion battery packs, optimizing charge and discharge cycles to enhance battery attributes like cycle life and state of charge, while accommodating dynamic user requirements through multiple charging and discharging stages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the battery is charged to 100% state of charge, then the vehicle range is maximized, but the battery cycle life is reduced
Solution Approach 1:
The patent implements dynamic adjustment of the charge profile by the controller based on real-time battery state assessment. The charge voltage and current are dynamically modified during charging to optimize between range and cycle life, rather than using a fixed charging algorithm. This allows the system to adaptively balance the contradiction between maximizing vehicle range and preserving battery cycle life.
Solution Approach 2:
The patent changes the charging parameters (voltage and current) during the charging process to create an optimized charge profile. By modifying these parameters dynamically, the system can limit the state of charge to a level that maximizes cycle life while still providing sufficient vehicle range, thereby resolving the contradiction between range maximization and cycle life preservation.
2Productivity
If fast charging is applied to reduce charging time, then the charging speed is improved, but the battery degradation accelerates
Solution Approach 1:
The controller dynamically adjusts the charge profile parameters during fast charging to optimize the balance between charging speed and battery degradation. By continuously monitoring battery state and modifying voltage and current in real-time, the system can achieve fast charging while limiting the acceleration of battery degradation through adaptive parameter control.
Solution Approach 2:
The patent applies partial fast charging by implementing an optimized charge profile that provides sufficient charging speed for practical purposes while avoiding the excessive charging rates that would cause severe degradation. The system delivers enough charging power to meet user needs while deliberately limiting the charge to prevent excessive stress on the battery.
3Measurement precision
If deep discharge is used to accurately measure battery capacity, then the measurement precision is improved, but the battery lifetime is dramatically shortened
Solution Approach 1:
The patent implements a method where the battery management system continuously monitors and assesses battery capacity during normal operation without requiring deep discharge events. The controller uses ongoing charge/discharge cycle data and state-of-charge measurements to self-determine battery capacity, eliminating the need for destructive deep discharge testing while maintaining accurate capacity tracking throughout the battery's life.
4Productivity
If the charge voltage is increased to reduce charging time, then the charging efficiency is improved, but the battery stress and degradation increase
Solution Approach 1:
The controller dynamically adjusts the charge voltage during the charging process to optimize the balance between charging efficiency and battery stress. By modifying voltage in real-time based on battery state, the system can apply higher voltages when appropriate to improve charging speed while limiting voltage levels to prevent excessive stress and degradation, thereby dynamically resolving the contradiction between efficiency and stress.
Data Source
AI summary
A system and method for improving cycle lifetimes for a lithium-ion battery pack, particularly for adapting to a dynamic use profile for a user. A battery cell pack charging system, including a charger and a controller, for charging a lithium-ion battery cell pack, the battery cell pack charging system has a circuit for charging the battery cell pack using an adjustable charging system including an adjustable charge profile to charge the battery cell pack wherein the adjustable charge profile includes: an operational parameter identifying a next operation post-charge performance characteristic for the battery cell pack wherein a controller determines a next cycle plan for the battery cell pack that provides the performance characteristic while concurrently enhancing an attribute of the battery cell pack and wherein the attribute is measured over a plurality of applied cycles; and one or more charging stages to produce an energy ending point for the plan; wherein the adjustable charge plan is implemented by the charger in anticipation of a post-charging operation associated with the operational parameter.