LiMnFePO4 Battery Charging Cutoff for Faster Full Charge
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Solution Overview
Problem
Lithium manganese iron phosphate batteries require an excessively long charging time to reach a fully charged state, failing to meet the demand for fast battery charging due to their low lithium deintercalation speed and poorer kinetic performance during constant-voltage charging.
Innovation Solution
A charging method involving constant-voltage charging until a first cutoff voltage is reached, followed by terminating at a target current greater than the first current, and then performing second-stage constant-current charging to enhance lithium deintercalation and capacity utilization, with specific voltage and current ranges optimized to reduce charging time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional constant-voltage charging is performed until the battery reaches a fully charged state (first current), then the battery capacity is fully utilized, but the charging time is excessively long
Solution Approach 1:
The patent applies partial action by terminating constant-voltage charging when the charging current reaches a target current that is greater than the first current (cutoff current). This means the charging process stops before the battery reaches 100% capacity, accepting that a portion of the capacity (corresponding to the current from target current to first current) remains slightly undercharged. This trade-off significantly reduces charging time while maintaining acceptable capacity utilization, as the battery is charged to a sufficient level for practical use without waiting for complete saturation.
2Quantity of substance
If constant-voltage charging is performed to fully deintercalate lithium ions, then capacity advantage is fully utilized, but the kinetic performance limitation causes significantly longer charging time
Solution Approach 1:
The patent changes the critical parameter of cutoff current from the conventional first current (corresponding to full charge) to a target current that is greater than the first current. This parameter change shifts the charging termination condition to an earlier stage during constant-voltage charging. By adjusting this current threshold parameter, the system accepts slightly less complete lithium ion deintercalation in exchange for dramatically improved charging speed, effectively optimizing for productivity while maintaining sufficient capacity utilization.
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
The method significantly reduces the constant-voltage charging time of lithium manganese iron phosphate batteries, ensuring they reach a fully charged state efficiently while maintaining capacity and lifespan.
Implementation Method 1
due to a low lithium deintercalation speed of a lithium manganese iron phosphate battery
Implementation Method 2
charging a secondary battery; and under a condition that a battery voltage of the secondary battery reaches a first cutoff voltage, performing constant-voltage charging on the secondary battery
Data Source
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AI summary
This application discloses a charging method and apparatus, an electronic device, and a computer-readable storage medium, where the method includes: charging a secondary battery; and under a condition that a battery voltage of the secondary battery reaches a first cutoff voltage, performing constant-voltage charging on the secondary battery, and terminating the constant-voltage charging when a charging current of the secondary current reaches a target current; where the target current is greater than a first current, and the first current refers to a current at which a capacity of the secondary battery reaches a fully charged state during constant-voltage charging. A positive electrode active material of the secondary battery includes LiMPO4, where M includes Mn and Fe elements.