Si-Ti-Ni Negative Electrode Material for Lithium Battery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium batteries using non-carbonaceous materials like Si suffer from unstable structure and decreased cycle life due to volumetric expansion and contraction during lithium ion intercalation and deintercalation, leading to lower capacities and cycle characteristics.
Innovation Solution
A negative active material comprising Si, Ti, and Ni particles with composite particles of Cu, Fe, Ni, Au, Ag, Pd, Cr, Mn, Ti, B, or P deposited on the surface of Si-Ti-Ni particles, which enhances electrical conductivity and suppresses side reactions, improving cycle characteristics and capacity retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If non-carbonaceous materials like Si are used as negative active material, then capacity is improved, but cycle life and structural stability deteriorate due to volumetric expansion and contraction
Solution Approach 1:
The patent applies the nesting principle by placing Si particles inside a matrix phase formed by alloying elements (Al, Ti, Ni, Co, Fe, Mn, or their combinations). This core-shell-like structure allows the Si core to provide high capacity while the surrounding matrix shell constrains volumetric expansion and maintains structural stability during cycling, thereby improving cycle life without sacrificing capacity
Solution Approach 2:
The patent creates composite materials by combining Si with alloying elements to form a matrix phase. This composite structure integrates the high capacity advantage of Si with the structural stability of the alloy matrix, resolving the contradiction between capacity and cycle life through material composition optimization
2Stability of the object's composition
If Si-based alloys with two phases (active Si phase and inactive matrix phase) are used, then structural stability is improved, but capacity decreases compared to pure silicon
Solution Approach 1:
The patent applies parameter changes by optimizing the composition ratios of Si and alloying elements, controlling particle size distribution, and adjusting the volume fraction of the matrix phase. These parameter optimizations maximize the active Si content while maintaining sufficient matrix support, thereby improving capacity without compromising structural stability
3Reliability
If carbonaceous materials are used as negative active material, then cycle life is improved, but capacity is lower compared to non-carbonaceous materials
Solution Approach 1:
The patent changes the material composition parameter from carbonaceous to non-carbonaceous (Si-based) materials, combined with optimized alloying element ratios and particle size parameters. This parameter transformation enables achieving both high capacity from Si and improved cycle life through the stabilizing matrix phase and surface treatment
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 approach results in a lithium battery with improved electrical conductivity, cycle characteristics, and capacity retention rates by reducing volumetric changes and enhancing the conductivity of the negative active material.
Implementation Method 1
composite particles of Cu, Fe, Ni, Au, Ag, Pd, Cr, Mn, Ti, B, or P deposited on the surface of Si-Ti-Ni particles, which enhances electrical conductivity
Implementation Method 2
composite particles comprising a plurality of second particles in which at least one element selected from the group consisting of Cu, Fe, Ni, Au, Ag, Pd, Cr, Mn, Ti, B, and P is partially or completely deposited on surface(s) of other of first particles
Data Source
AI summary
A negative active material for a lithium battery with an improved cycle characteristic and capacity retention rate, and the negative active material comprises a plurality of particles comprising a plurality of first particles comprising Si, Ti, and Ni; and composite particles comprising a plurality of second particles in which at least one element selected from the group consisting of Cu, Fe, Ni, Au, Ag, Pd, Cr, Mn, Ti, B, and P is partially or completely deposited on surface(s) of other of first particles, a method of preparing the negative active material, and a lithium battery including a negative electrode including the negative active material.