Composite Positive Electrode Plate for Battery Voltage Self-Balancing
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Solution Overview
Problem
Lithium iron phosphate batteries experience inaccurate remaining power display and rapid capacity fading, affecting user experience due to inadequate voltage self-balancing and capacity retention performance.
Innovation Solution
A positive electrode plate comprising a lithium iron phosphate-based material combined with secondary active materials like lithium nickelate, lithium manganate, or lithium cobaltate, which balances internal voltage differences and adjusts state of charge, improving capacity retention and power display accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium iron phosphate material is used as the positive electrode active material, then safety and cost are improved, but remaining power display accuracy and capacity retention performance deteriorate
Solution Approach 1:
The patent uses a composite positive electrode active material consisting of lithium iron phosphate (LiFePO4) and lithium nickel cobalt manganate (LCM) in a specific weight ratio range (95:5 to 50:50). This composite structure combines the safety advantages of LFP with the voltage characteristics of LCM, enabling both accurate remaining power display through voltage differentiation and maintained safety performance.
2Reliability
If lithium iron phosphate material is used as the positive electrode active material, then safety and cost are improved, but capacity retention performance deteriorates
Solution Approach 1:
The composite structure of LFP and LCM in specific proportions improves capacity retention performance by leveraging the complementary electrochemical characteristics of both materials, while maintaining the inherent safety advantages of lithium iron phosphate.
3Device complexity
If single active material is used in the positive electrode plate, then device complexity is reduced, but voltage self-balancing performance deteriorates
Solution Approach 1:
The patent employs a composite active material system combining LFP and LCM with different voltage plateaus, which enables voltage self-balancing through intrinsic voltage differentiation between the two materials during charge-discharge cycles, improving voltage self-balancing performance without significantly increasing structural complexity.
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 combination of lithium iron phosphate and secondary active materials enhances voltage self-balancing, leading to improved capacity retention and accurate power display, thereby enhancing user experience and safety performance of lithium iron phosphate batteries.
Implementation Method 1
a first active material selected from a lithium iron phosphate-based material represented by a formula LiFe1-xMnxPO4... a second active material including one or more selected from lithium nickelate, lithium manganate, lithium cobaltate... the secondary battery using the positive electrode plate has a good voltage self-balancing performance
Data Source
AI summary
A positive electrode plate includes a first active material and a second active material. The first active material is selected from a lithium iron phosphate-based material represented by a formula LiFe1-xMnxPO4, where x is between 0-0.8. The second active material includes one or more of lithium nickelate, lithium manganate, lithium cobaltate, lithium nickel cobalt manganate, lithium nickel cobalt aluminate, a lithium-rich manganese base, and lithium vanadium phosphate. An amount of the second active material used accounts for, by mass, 10-70%, on the basis of a total mass of the first active material and the second active material.