Negative Electrode Sheet Porosity for Faster Li-Ion Transport
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Solution Overview
Problem
Conventional methods to enhance lithium-ion battery performance by modifying negative active materials are costly and only improve carrier diffusion within the materials, not between them, limiting rate performance.
Innovation Solution
A negative electrode sheet comprising a current collector with a negative electrode active material layer containing 0.1% to 5% inorganic porous material, which improves ionic conductivity and electrolyte absorption, shortening carrier conduction paths and mitigating polarization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If inorganic porous material is added to shorten carrier conduction path and reduce polarization, then rate performance is improved, but excessive content increases device complexity and cost
Solution Approach 1:
The patent applies parameter changes by limiting the inorganic porous material content to a maximum of 5% of the total mass of the negative electrode active material layer. This controlled parameter ensures rate performance improvement through shortened carrier conduction paths and reduced polarization, while avoiding excessive content that would unnecessarily increase device complexity and manufacturing cost.
2Reliability
If conventional methods modify negative active materials to increase carrier mobility, then carrier diffusion within materials is improved, but diffusion between materials is not significantly improved and costs increase
Solution Approach 1:
The patent introduces inorganic porous material as an intermediary component within the negative electrode active material layer. This intermediary substance creates optimized pore structures that facilitate carrier diffusion between different negative active material particles, addressing the limitation of conventional modification methods that only improve diffusion within individual materials without significantly enhancing inter-particle diffusion.
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 inorganic porous material enhances the rate performance and cycle life of the battery by optimizing pore structure and electrolyte distribution, while maintaining electrochemical stability and mechanical integrity.
Implementation Method 1
Pores in the inorganic porous material can absorb electrolyte
Implementation Method 2
During battery charging/discharging, the electrolyte permeates from the pores of the inorganic porous material to the negative active material, shortening a conduction path of carriers (lithium ions), thereby reducing or mitigating polarization phenomena in the negative electrode sheet
Data Source
Figure 1
AI summary
A negative electrode sheet, a battery and an electric device. The negative electrode sheet comprises a current collector and a negative electrode active material layer that coats at least one surface of the current collector, wherein the negative electrode active material layer comprises a negative electrode active material, an inorganic porous material and a binder, and the inorganic porous material accounts for 0.1%-5% of the total mass of the negative electrode active material layer.