Electrode Recess and Separator Pairing for Low-Drop Batteries
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Solution Overview
Problem
The formation of recesses on electrode plates by laser ablation in batteries leads to electrode powder accumulation, increasing the risk of separator puncture, high voltage drop, and short circuits, adversely affecting battery safety and performance.
Innovation Solution
A battery design with controlled recess parameters on the first coating, including specific air permeability and width of the recess, and a separator configuration that minimizes powder accumulation, enhancing ion transmission and reducing the risk of short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If recesses are formed on electrode plates by laser ablation to improve rate capability, then dynamics performance is improved, but electrode powder accumulates in recesses increasing risk of separator puncture and short circuits
Solution Approach 1:
The separator acts as an intermediary component between the electrode plate with recesses and the electrolyte. By optimizing separator air permeability (500-1500 mD) and thickness, it mediates the conflict between allowing ion transport through recesses and preventing powder-induced short circuits, thus improving safety while maintaining rate capability
Solution Approach 2:
The invention changes physical parameters of the separator (air permeability S from 500-1500 mD, thickness L from 15-30 μm) to optimize the balance between ion transmission and safety. The product S×L is controlled within 7500-45000 μm·sec/100 cc to simultaneously achieve high rate capability and reduced short circuit risk
2Productivity
If recess width is increased to enhance ion transmission, then rate capability improves, but powder accumulation risk increases
Solution Approach 1:
The invention optimizes the recess width parameter L to be within 15-30 μm, which is wide enough to facilitate ion transmission and improve rate capability, yet narrow enough to minimize powder accumulation. This parameter optimization is combined with separator air permeability control to achieve the desired balance
3Loss of energy
If separator air permeability is increased to reduce voltage drop, then ion transmission improves, but powder may more easily pass through causing short circuits
Solution Approach 1:
The invention optimizes separator air permeability S to be within 500-1500 mD, which reduces voltage drop by improving ion transmission while maintaining sufficient filtration capability to prevent powder-induced short circuits. The synergistic control of S×L product ensures both low voltage drop and high safety
Solution Approach 2:
The separator is designed as a composite structure with optimized porosity and pore size distribution, combining high air permeability for ion transport with appropriate filtration characteristics to block powder particles, thus achieving both low voltage drop and high reliability
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
Improves the rate capability and reduces voltage drop while ensuring safety and cycle life by optimizing the recess parameters and separator properties.
Implementation Method 1
During charge/discharge cycling of the battery, active ions (e.g., lithium ions in a lithium-ion battery) pass through the separator
Implementation Method 2
The formation of a recess on a surface of the electrode plate by laser ablation
Data Source
AI summary
The disclosure provides a battery, including a first electrode plate and a separator, the first electrode plate including a first current collector and a first coating located on a surface of the first current collector. The first coating is connected to the separator; and a surface of the first coating is provided with a recess, and an air permeability S of the separator and a width L of the recess satisfy: 5000 μm·sec/100 cc≤S×L≤75,000 μm·sec/100 cc, where S is in sec/100 cc and L is in μm. The disclosure can improve the rate capability of the battery while reducing the voltage drop of the battery and reducing the risk of short circuit.