Elastic Cell Stack Clamping for Silicon Electrode Expansion
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Solution Overview
Problem
Lithium-ion battery electrodes experience deformation due to the expansion of silicon particles during charging, leading to reduced contact area and impaired charge acceptance and release capabilities.
Innovation Solution
A clamping device for electrochemical cell stacks is designed with movable plates and an elastic member to adjust pressure and accommodate expansion, reducing deformation and maintaining consistent pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon particles are used as active material for the negative electrode to increase energy density, then volumetric and gravimetric energy densities are improved, but electrode deformation occurs during cycling due to expansion upon charging
Solution Approach 1:
The clamping device employs movable plates that can dynamically adjust their position to accommodate the expansion and contraction of the electrode during charging and discharging cycles. This dynamic adjustment prevents deformation while maintaining consistent contact pressure, allowing the use of high-capacity silicon particles without suffering from their expansion-induced shape changes.
2Volume of moving object
If the layers of the cell stack are confined in a tight region, then space utilization is improved, but expansion of silicon particles during charging results in warping or deformation of the metal foil
Solution Approach 1:
The clamping device uses movable plates that can shift position to accommodate volume changes during charging. This allows the cell stack to maintain tight confinement for efficient space utilization while the plates dynamically adjust to prevent warping of the metal foil during silicon particle expansion.
Solution Approach 2:
The clamping device maintains consistent clamping pressure on the cell stack despite changes in electrode volume during charging. By adjusting the position of movable plates, the system keeps the contact pressure parameter constant, preventing metal foil warping while allowing necessary volume expansion.
3Shape
If consistent pressure is maintained on the electrochemical cell stack during charging, then electrode deformation is reduced, but the expansion of the cell stack increases the pressure exerted by the plates
Solution Approach 1:
The clamping device employs movable plates that can dynamically adjust their position in response to cell stack expansion. As the stack expands during charging, the plates move outward, maintaining consistent clamping pressure without creating excessive stress, thereby preventing electrode deformation while accommodating volume changes.
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 clamping device effectively reduces electrode deformation and maintains consistent pressure on the cell stack, enhancing the battery's ability to accept and release electrical charge and improving cycle life.
Implementation Method 1
The elastic member can be configured to be compressed during the charging of the electrochemical cell stack, thereby reducing the increase in pressure on the electrochemical cell stack exerted by the first and second plates
Data Source
AI summary
A clamping device for an electrochemical cell stack is provided. The clamping device can include a first plate and a second plate. The second plate can be positionable relative to the first plate such that a space between the first plate and the second plate can be sized to receive an electrochemical cell stack. The device also can include a coupling member coupling the first plate to the second plate. At least one of the first and second plates can be movable away from the other plate. The coupling member can have a first end portion and a second end portion. The device further can include an elastic member disposed between the first end portion and the second end portion.