Silicon Anode Particle Orientation to Limit Electrode Expansion
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Solution Overview
Problem
Silicon-based negative electrode materials in lithium-ion batteries face challenges such as unstable solid-electrolyte interphase formation and volume expansion during charging and discharging, limiting their high-power, long-life, and fast-charging capabilities.
Innovation Solution
A negative electrode active material with metal-containing particles oriented at specific angular conditions (60° to 90°) is developed, combined with a core-shell or hollow structure and carbon-based materials, to mitigate volume expansion and enhance battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon-based negative electrode materials are used to achieve high energy density, then battery capacity is improved, but volume expansion occurs during charging and discharging
Solution Approach 1:
The silicon-based negative electrode material is divided into particles with specific angular characteristics (60° to 90° angles), segmenting the bulk silicon into controlled angular particles that can better manage volume expansion during lithiation and delithiation cycles
Solution Approach 2:
The invention uses composite materials by combining silicon-based materials with carbon materials through surface coating or composite layer formation, creating a composite structure that maintains high capacity while suppressing volume expansion through the carbon matrix
2Stability of the object's composition
If surface coating or composite layer formation using carbon materials is applied to solve volume expansion, then electrode stability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The invention changes the angular parameters of silicon particles to specific ranges (60° to 90°), using geometric parameter control as a simpler alternative to complex surface coating processes while achieving similar stability benefits
3Reliability
If surface treatments using carbon materials are applied to improve reversibility, then electrochemical properties are enhanced, but manufacturing cost increases
Solution Approach 1:
The invention uses angular parameter control (60° to 90°) of silicon particles as a cost-effective manufacturing approach that achieves improved electrochemical reversibility without the high costs associated with carbon-based surface treatments
4Quantity of substance
If silicon-based negative electrode materials are used to achieve high capacity, then energy density is improved, but unstable solid-electrolyte interphase forms due to side reactions
Solution Approach 1:
The invention creates composite structures where silicon-based particles are combined with carbon materials, forming a composite that maintains high capacity while the carbon component suppresses harmful side reactions and stabilizes the solid-electrolyte interphase
Data Source
AI summary
The present invention relates to a negative electrode active material including metal-containing particles, wherein at least one of the angles, each angle formed between a straight line connecting the center point of the negative electrode active material and the center point of each of the metal-containing particles and the long axis of a corresponding one of the metal-containing particles, is in a range of 60° to 90°. The present invention also relates to a method of manufacturing the negative electrode active material and to a lithium secondary battery including the negative electrode active material.