Electrode materials and Si alloy composite powders for lithium-ion batteries

A composite electrode material with Si alloy powder and graphite addresses the volume expansion issue in Si-based batteries, enhancing both initial discharge capacity and cycle characteristics through controlled expansion and distribution, resulting in improved battery performance.

JP7852645B2Active Publication Date: 2026-04-28DAIDO STEEL CO LTD
3 Cites 0 Cited by

Patent Information

Application Number
JP2023551488
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Priority Date
2021-09-30
Filing Date
2022-09-26
Publication Date
2026-04-28
Estimated Expiration
2042-09-26

AI Technical Summary

Technical Problem

Conventional lithium-ion batteries using silicon (Si) as a negative electrode material face significant volume expansion and contraction due to alloying reactions with lithium ions, leading to particle cracking and detachment from the current collector, which degrades cycle characteristics and capacity maintenance.

Method used

A composite electrode material comprising graphite powder mixed with Si alloy powder, where the Si alloy powder consists of Si particles, Si-X compound particles, and optionally Sn-Y or Al-Y compound particles, with a controlled average particle size and surface coverage, allowing for independent expansion of Si particles and reducing stress concentration.

Benefits of technology

The composite material effectively suppresses Si particle collapse and enhances both initial discharge capacity and cycle characteristics by providing a buffer region for Si expansion and ensuring even distribution, thereby improving battery performance.

✦ Generated by Eureka AI based on patent content.
Patent Text Reader

Abstract

The present invention pertains to an electrode material for lithium-ion batteries, in which: graphite powder and an Si alloy composite powder are mixed; the Si alloy composite powder has an average particle diameter of 5 μm or less, and contains Si particles, Si-X compound particles (X=Fe, Ni, Cr, Co, Mn, Zr, Ti), and at least one of Sn-Y compound particles (Y=Cu, Fe, Ni, Cr, Co, Mn, Zr, Ti) and Al-Y compound particles; the proportion of the Si particles in the Si alloy composite powder is 30-95 mass%; and, the coverage of the surface of the graphite particles by the Si alloy composite powder is 5% or greater.
Need to check novelty before this filing date? Find Prior Art