Electrode Recess Geometry in Batteries to Limit Voltage Drop
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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 and voltage drop, which affects 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 thickness and spacing that satisfy 5000≤S×L≤75,000, enhancing the 5C constant current charging rate and reducing voltage drop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If recesses are formed on electrode plates by laser ablation to improve rate capability, then the 5C constant current charging rate is improved, but electrode powder accumulates in the recesses increasing the risk of separator puncture and voltage drop
Solution Approach 1:
The patent applies local quality by creating recesses with specific dimensional characteristics (width L and depth H) in localized areas of the electrode plate surface. The recesses are designed with controlled geometry where the width-to-depth ratio satisfies 0.05 ≤ L/H ≤ 0.5, creating specific local structures that facilitate powder ejection while maintaining overall electrode integrity. This local structural modification enables differentiated functionality in different regions of the electrode surface.
Solution Approach 2:
The patent employs parameter changes by optimizing the recess dimensions (width L and depth H) and their spatial distribution (spacing D) to satisfy specific mathematical relationships: 0.05 ≤ L/H ≤ 0.5 and 0.5 ≤ D/L ≤ 5. These parameter optimizations transform the recess structure from a simple geometric feature into a functional element that controls powder behavior during charging/discharging cycles, thereby reducing separator puncture risk while maintaining high rate capability.
2Speed
If recesses are formed on electrode plates to enhance dynamics performance, then the battery rate capability is improved, but the voltage drop increases due to powder accumulation
Solution Approach 1:
The patent creates localized recess structures with specific geometric properties (width L, depth H, and spacing D) that satisfy 0.05 ≤ L/H ≤ 0.5 and 0.5 ≤ D/L ≤ 5. These locally optimized structures facilitate efficient ion transport and powder ejection in specific regions, thereby improving overall rate capability while minimizing energy losses from powder accumulation.
Solution Approach 2:
The patent optimizes the dimensional parameters of the recesses (width L, depth H, and spacing D) to satisfy specific ratio relationships. By controlling L/H between 0.05-0.5 and D/L between 0.5-5, the recesses achieve optimal performance in facilitating ion transport and powder removal, thereby improving rate capability while reducing voltage drop associated with powder accumulation.
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 safety of the battery by increasing the 5C constant current charging rate to 60% or more and reducing voltage drop to 0.018 or less, while minimizing the risk of short circuits.
Implementation Method 1
an air permeability S of the separator
Implementation Method 2
The formation of a recess on a surface of the electrode plate by laser ablation or the like
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≤S×L≤75,000, 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.