Silicon Negative Electrode Skeleton for Durable High-Density Batteries
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Solution Overview
Problem
Non-aqueous electrolyte secondary batteries face limitations in increasing negative electrode thickness and active material density due to manufacturing constraints, leading to issues with durability and energy density.
Innovation Solution
A non-aqueous electrolyte secondary battery negative electrode featuring a porous metal collector with a silicon-based active material, a silicate skeleton-forming agent having a siloxane bond, a conductivity aid, and a binder, which enhances durability and energy density by forming a stable interface layer and improving electron conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the film thickness of the negative electrode is increased to improve energy density, then the energy density is improved, but manufacturing problems such as coating unevenness, cracking, and peeling occur
Solution Approach 1:
The patent employs a porous metal body as the collector structure, which provides a three-dimensional framework that supports thicker negative electrode materials without compromising structural integrity. The porous structure allows for better stress distribution and reduces the likelihood of cracking and peeling during manufacturing and battery operation, enabling increased film thickness while maintaining manufacturing precision.
2Quantity of substance
If the amount of negative electrode active material per unit area is increased to improve energy density, then the energy density is improved, but the binding force between binder and active material becomes insufficient, reducing durability
Solution Approach 1:
The patent utilizes a composite structure consisting of a porous metal body collector combined with negative electrode material. This composite approach provides enhanced mechanical strength and binding force compared to conventional foil collectors. The porous metal framework acts as a robust skeleton that maintains structural integrity even when large amounts of active material are applied, thereby improving durability while enabling higher active material capacity per unit area.
3Quantity of substance
If high-capacity silicon-based materials are used to improve energy density, then the energy density is improved, but the expansion and contraction during charging and discharging causes deterioration in durability
Solution Approach 1:
The porous metal body structure provides a flexible yet strong framework that can accommodate the significant expansion and contraction of silicon-based active materials during charging and discharging cycles. The porous architecture allows for volume changes without causing structural failure or delamination, thereby maintaining durability and cycle life even when using high-capacity silicon-based materials.
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 solution effectively suppresses deterioration in durability and enhances energy density by stabilizing the negative electrode structure and improving cycle life, even with high-capacity silicon-based materials that expand significantly during charging and discharging.
Implementation Method 1
a skeleton-forming agent containing a silicate having a siloxane bond
Implementation Method 2
a collector formed of a porous metal body
Data Source
AI summary
An object is to provide a non-aqueous electrolyte secondary battery negative electrode that can suppress a deterioration in durability and improve energy density, and a non-aqueous electrolyte secondary battery including the same. A non-aqueous electrolyte secondary battery negative electrode, comprising: a collector formed of a porous metal body, and a negative electrode material disposed in pores of the porous metal body, wherein the negative electrode material comprises a negative electrode active material formed of a silicon-based material, a skeleton-forming agent comprising a silicate having a siloxane bond, a conductivity aid, and a binder.