Battery Cell Structure With Deformation-Absorbing Electrode Layers
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Solution Overview
Problem
The repeated expansion and contraction of negative and positive electrodes in lithium secondary batteries cause deformation of the battery case, leading to potential damage and inefficiencies in battery modules.
Innovation Solution
Incorporating a deformation absorbing member made of conductive plastic with a porosity of 50% to 70% between the negative and positive electrode current collectors, which expands and contracts to accommodate the thickness changes of the electrodes, maintaining the case's structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If electrodes are accommodated in a rigid case, then structural support is provided, but electrode expansion and contraction causes case deformation
Solution Approach 1:
The patent introduces a deformation absorbing member with flexible properties that can expand and contract to accommodate electrode volume changes during charging and discharging cycles. This flexible component is positioned between the electrode and the rigid case, allowing the case to maintain its rigid structural support while the flexible member absorbs the dimensional changes, preventing case deformation.
Solution Approach 2:
The deformation absorbing member serves as an intermediary element between the electrode and the case. It mediates the interaction by absorbing the expansion and contraction forces generated by the electrode during operation, thereby protecting the case from deformation while maintaining structural integrity.
2Stability of the object's composition
If additional structural support is added to prevent case deformation, then case stability is improved, but device complexity increases
Solution Approach 1:
The patent extracts the deformation absorption function from the case structure itself and places it in a separate, dedicated deformation absorbing member. This allows the case to maintain simple rigid structural support while the separate flexible member handles the complexity of accommodating electrode expansion and contraction, thereby preventing case deformation without increasing overall device 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
Prevents deformation of the battery case by absorbing the expansion and contraction of electrodes, reducing the need for additional structural support in battery modules and improving assembly efficiency.
Implementation Method 1
the deformation absorbing member may be pressurized or stretched by at least one of the negative electrode and the positive electrode to contract or expand
Implementation Method 2
The deformation absorbing member may be formed of a material including conductive plastic having a porosity of 50% or more to 70% or less
Data Source
AI summary
A battery cell includes a case provided with an accommodation space; and an electrode assembly accommodated in the accommodation space and contacting the case. The electrode assembly includes a negative electrode including a plurality of negative electrode current collectors, on which a negative electrode mixture is coated, and a deformation absorbing member interposed between the plurality of negative electrode current collectors; a positive electrode including a positive electrode current collector on which a positive electrode mixture is coated; and a separator interposed between the negative electrode mixture and the positive electrode mixture. The deformation absorbing member may be interposed between surfaces, opposing a surface on which the negative electrode mixture is coated, of the negative electrode current collector and may be pressurized or stretched by at least one of the negative electrode and the positive electrode to contract or expand.