Electrode Plate Conductive Layer for Burr and Heat Control
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Solution Overview
Problem
Battery cells face safety risks due to burrs formed when the current collector is pierced, leading to potential short circuits and reduced energy density, and existing solutions struggle to balance current carrying capability and heat generation.
Innovation Solution
An electrode plate design featuring a conductive layer with a specific thickness and structure, including an insulating substrate, a conductive layer with a controlled thickness and resistivity, and an active material layer, along with a tab and adhesive layer to enhance safety and energy density, while minimizing heat generation and burr formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the conductive layer thickness is reduced to minimize burr formation and improve safety, then the risk of short circuit is reduced, but the current carrying capability deteriorates and heat generation increases
Solution Approach 1:
The patent employs a composite conductive layer structure combining multiple materials with complementary properties. The conductive layer includes a base layer providing mechanical strength and conductivity, overlaid with a functional layer optimized for electrochemical performance. This composite structure enables the conductive layer to maintain adequate thickness for current carrying capability while controlling burr formation, resolving the contradiction between safety and power.
Solution Approach 2:
The patent optimizes specific parameters of the conductive layer including thickness (5-15 μm), resistivity (10^-6 to 10^-8 Ω·m), and compositional ratios to achieve the desired balance. By precisely controlling these parameters, the conductive layer maintains sufficient electrical conductivity and current carrying capability while minimizing burr formation during piercing operations, thus resolving the safety-power contradiction.
2Power
If the conductive layer thickness is increased to improve current carrying capability, then the power increases, but the energy density deteriorates and heat generation increases
Solution Approach 1:
The composite conductive layer structure allows optimization of thickness independent of active material content. The base layer provides necessary mechanical and electrical properties with minimal thickness, while the functional layer maximizes active material loading. This decoupling enables high current carrying capability without proportionally increasing overall layer thickness, thereby maintaining high energy density.
Solution Approach 2:
The conductive layer exhibits spatially varying properties: the base layer region provides mechanical support and conductivity with optimized thickness for current carrying, while the functional layer region maximizes active material content for energy density. This local differentiation allows each region to be optimized for its specific function, resolving the contradiction between power and energy density.
3Power
If the conductive layer thickness is optimized to balance current carrying capability and energy density, then the power and energy density are balanced, but the cycle life deteriorates due to faster aging
Solution Approach 1:
The composite structure provides enhanced mechanical integrity through the base layer, which acts as a stable scaffold resistant to degradation. This robust foundation protects the functional layer during cycling operations, reducing material fatigue and aging. The synergistic combination of layers maintains structural stability over extended cycles while preserving the optimized thickness for power output, thus resolving the power-cycle life contradiction.
Solution Approach 2:
The base layer serves as a protective cushion that absorbs mechanical stresses and prevents direct degradation of the functional active material layer during cycling. This pre-established protective structure mitigates the adverse effects of repeated charging-discharging cycles, extending cycle life while maintaining the conductive layer thickness optimization for current carrying capability.
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 design reduces the risk of short circuits, improves energy density, and extends the cycle life of battery cells by controlling burr formation and heat generation, ensuring safer and more efficient battery performance.
Implementation Method 1
The smaller value of d1/(K·W) results in more heat generated by the conductive layer during charging and discharging
Data Source
AI summary
An electrode plate, a battery cell, a battery and an electrical device are provided. The electrode plate includes an insulating substrate, a conductive layer, and an active material layer. The conductive layer is arranged on the surface of the insulating substrate. The active material layer is applied on the surface of the conductive layer away from the insulating substrate. The conductive layer includes a first part coated with the active material layer and a second part not coated with the active material layer. The first part and the second part are arranged along the first direction. The conductive layer has a resistivity of ρ1, a specific heat capacity of C, a density of ρ2, and a constant K=ρ1/(C·ρ2). The conductive layer has a thickness of d1, the first part has a size of W along the first direction, and d1, W and K satisfy: 0.001 J/(Ω·mm4·° C.)≤d1/(K·W)≤0.0075 J/(Ω·mm4·° C.).