Lithium-Ion Battery Separator with Ion Storage for Capacity Regeneration
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Solution Overview
Problem
Lithium-ion accumulators experience capacity loss due to consumption of exchangeable lithium ions during the formation stage, leading to reduced capacity and potential overvoltages, which can cause structural and chemical degradation of active insertion materials.
Innovation Solution
The solution involves modifying the separator to store and regenerate lithium ions within the accumulator, allowing for the reinjection of ions into the active electrode materials, thereby regenerating the lost capacity without adding complexity to the accumulator's architecture or compromising mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium ions are consumed during the formation stage, then the battery structure is stabilized, but the capacity is reduced and overvoltages occur
Solution Approach 1:
The separator is pre-loaded with lithium ions during manufacturing before the battery is put into service. This preliminary action ensures that when over-discharge or formation occurs, the separator can release stored lithium ions to maintain electrode potential and prevent overvoltages, thereby resolving the contradiction between structural stabilization and capacity maintenance.
Solution Approach 2:
The separator serves a dual function: it acts as both a physical barrier between electrodes and a lithium ion reservoir. The separator autonomously releases lithium ions when electrodes experience potential drops, without requiring external intervention. This self-service mechanism maintains battery capacity and prevents overvoltages while allowing the formation process to stabilize the structure.
2Quantity of substance
If a capacity regenerator is added to the accumulator, then lost capacity can be recovered, but the device complexity increases
Solution Approach 1:
The separator is designed to perform multiple functions simultaneously: it provides physical separation between electrodes, allows ion transport during normal operation, and serves as a lithium ion reservoir for capacity regeneration. By making the separator multi-functional, the patent eliminates the need for separate regenerator components, thereby recovering lost capacity without increasing device complexity.
Solution Approach 2:
The capacity regeneration function is merged into the separator structure itself. The separator combines the barrier function with a lithium ion storage function, creating an integrated component that eliminates the need for additional regenerator devices. This merging approach maintains structural simplicity while enabling capacity recovery.
3Quantity of substance
If the separator is used to store and release lithium ions, then capacity regeneration is optimized, but the separator's mechanical strength may be compromised
Solution Approach 1:
The separator is constructed as a composite material system combining a porous polymer matrix (such as polyethylene or polypropylene) with lithium ion-containing compounds. The polymer matrix provides mechanical strength and structural integrity, while the lithium ion compounds embedded within the matrix provide storage and release capabilities. This composite structure resolves the contradiction between ion storage capacity and mechanical strength.
Solution Approach 2:
The separator exhibits local quality differentiation where different regions or phases serve different functions. The polymer matrix regions provide mechanical support and structural stability, while the lithium ion-containing regions provide storage and release functionality. This spatial differentiation of properties allows the separator to simultaneously maintain strength and provide ion storage capacity.
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
This approach homogeneously reinjects ions into the electrodes, optimizing capacity regeneration, minimizing the distance between the ion source and target electrodes, and preventing overvoltages, thus extending the service life and maintaining mechanical integrity.
Implementation Method 1
electrochemical generators, which operate according to the principle of insertion or disinsertion, or in other words intercalation-disintercalation, of metal ions in at least one electrode
Implementation Method 2
the constituent may include a separator, in the form of one or more films, made of polymer or microporous composite, soaked in organic electrolyte(s) or of the ionic liquid type which allows the movement of Lithium ions from the cathode to the anode
Data Source
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AI summary
The present invention relates to a metal-ion electrochemical accumulator (A), such as a Li-ion accumulator, comprising at least one electrochemical cell C including a cathode (2), an anode (3) and a separator (1, 11, 12, 13), impregnated with an electrolyte, between the anode and the cathode, at least a part of the separator (1) including an exchangeable metal ion storage component.