Bent Electrode Assembly Barrier Layer Against Lithium Plating
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Solution Overview
Problem
Lithium plating in batteries leads to dendrite formation, which can cause internal short circuits and safety hazards, affecting both electrical and safety performance.
Innovation Solution
A barrier layer is disposed between the positive current collecting layer and the positive active material layer in the bend portions of the electrode assembly to prevent electron transport, thereby reducing lithium plating and enhancing battery safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the positive active material layer is directly coated on the positive current collecting layer in bend portions, then the battery capacity is improved, but lithium plating occurs and safety deteriorates
Solution Approach 1:
An insulating barrier layer is introduced as an intermediary between the positive active material layer and the positive current collecting layer in the bend portions. This barrier layer prevents direct electron transport while allowing the battery to maintain its capacity, thereby eliminating lithium plating and improving safety without sacrificing performance.
2Power
If electron transport is allowed between positive current collecting layer and positive active material layer in bend portions, then electrical performance is improved, but lithium plating occurs
Solution Approach 1:
The solution applies different electron transport properties to different regions of the positive electrode plate. In the bend portions, electron transport is blocked by the insulating barrier layer to prevent lithium plating, while in non-bend portions, electron transport remains unrestricted to maintain electrical performance. This localized differentiation resolves the contradiction between power and harmful effects.
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 barrier layer effectively prevents electron transport, minimizing lithium plating and improving battery safety and service life by reducing the likelihood of dendrite formation.
Implementation Method 1
A barrier layer is disposed between the positive current collecting layer and the positive active material layer in the bend portions of the electrode assembly to prevent electron transport
Data Source
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AI summary
Embodiments of this application provide an electrode assembly, a battery cell, a battery, and a method and device for manufacturing an electrode assembly. The electrode assembly includes a positive electrode plate and a negative electrode plate. The positive electrode plate and the negative electrode plate are wound or folded to form a bend region. The positive electrode plate includes a plurality of bend portions located in the bend region. Each bend portion includes a positive current collecting layer and a positive active material layer. The positive current collecting layer is coated with the positive active material layer on at least one surface in a thickness direction of the positive electrode plate. A barrier layer is disposed between the positive current collecting layer and the positive active material layer. The barrier layer is configured to prevent electron transport between the positive current collecting layer and the positive active material layer, thereby weakening or precluding delithiation reactions of the positive active material layer, and making the positive active material layer refrain from deintercalating lithium ions or deintercalate just a small quantity of lithium ions. Therefore, this solution reduces the probability of lithium plating or avoids occurrence of lithium plating, and in turn, improves battery safety.