Ionic Conductive Additive for Li-Ion Electrode Wetting and Swelling Control
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Solution Overview
Problem
The increasing surface and compaction density of lithium-ion battery electrode plates lead to smaller, non-uniform pores, making it difficult for electrolyte to wet evenly and causing increased direct current impedance and potential safety hazards due to lithium precipitation.
Innovation Solution
An ionic conductive additive with a resistivity greater than 10 Ω·m and oil absorption greater than 100 ml/100 g, formulated as a solid powder with a median particle size less than 50 μm, is used to enhance ionic conductivity while minimizing participation in electrode reactions, thus preventing battery expansion and capacity reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-oil-factor carbon black is used to improve ionic conductivity, then ionic conduction is enhanced, but carbon black participates in electrode reactions causing gas production and battery expansion
Solution Approach 1:
The patent divides the functional requirements into two separate components: conductive carbon black for ionic conductivity and alumina for structural stability and reaction inhibition. This segmentation allows each material to perform its specific function without the harmful side effects of carbon black participating in electrode reactions.
Solution Approach 2:
The patent creates a composite additive system combining conductive carbon black and alumina in specific proportions. This composite material leverages the ionic conductivity of carbon black while using alumina to prevent gas production and battery expansion, resolving the contradiction between conductivity enhancement and harmful gas generation.
2Reliability
If carbon black is used to enhance conductivity, then ionic conduction improves, but battery capacity reduces due to participating reactions
Solution Approach 1:
The patent separates the roles of carbon black and alumina, where carbon black provides ionic conduction and alumina prevents capacity loss by being electrochemically inert. This segmentation ensures that conductivity enhancement does not come at the cost of battery capacity.
Solution Approach 2:
The composite additive system combines conductive carbon black with alumina, where alumina acts as a protective component that prevents the carbon black from participating in harmful electrode reactions that would reduce battery capacity, while maintaining ionic conduction benefits.
3Quantity of substance
If electrode plate surface density and compaction density are increased, then energy density improves, but pore size decreases making electrolyte wetting difficult
Solution Approach 1:
The patent utilizes the porous structure of alumina particles to maintain electrolyte access within the compacted electrode. The porous nature of alumina provides pathways for electrolyte penetration even when the electrode plate pores are reduced due to high compaction density, thus maintaining ease of electrolyte wetting while achieving high energy density.
Solution Approach 2:
The composite additive system combines carbon black and alumina, where alumina's porous structure complements the compacted electrode matrix by providing additional electrolyte access channels, resolving the contradiction between high energy density and electrolyte wetting difficulty.
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 use of the ionic conductive additive effectively prevents battery expansion and capacity reduction by avoiding participation in electrode reactions, while ensuring sufficient ionic conduction and reducing the risk of lithium precipitation, thus enhancing battery performance and safety.
Implementation Method 1
the ionic conductive additive is for meeting the conductive requirements of lithium ions while reducing participating reactions in the positive and negative electrodes
Implementation Method 2
the resistivity of the ionic conductive additive is greater than 10 Ω·m
Implementation Method 3
the oil absorption of the ionic conductive additive is greater than 100 ml/100 g
Data Source
AI summary
An ionic conductive additive, an electrode plate group and a lithium-ion battery, where the resistivity of the ionic conductive additive is greater than 10 Ω·m; the oil absorption of the ionic conductive additive is greater than 100 ml/100 g; the ionic conductive additive is a solid powder; and the median particle size of the solid powder is less than 50 μm. The ionic conductive additive is used to meet the requirements of lithium-ion conductivity while reducing the participation in the reaction of positive and negative electrodes.