Lithiated Electrode Coating for Silicon Volume Expansion
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Solution Overview
Problem
Silicon-based electrode materials for batteries suffer from volume expansion during charging and discharging, leading to material rupture and poor cycle life and performance.
Innovation Solution
A lithiated electrode material is developed by coating an organic acid lithium salt layer on the surface of electrode active materials, which includes organic acid lithium salts formed by lithiating organic acids with at least two carboxyl groups, enhancing the electrode's performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If silicon-based materials are used as electrode active materials to pursue higher energy density, then energy density is improved, but volume expansion during charging and discharging leads to material rupture and poor cycle life
Solution Approach 1:
A coating layer comprising a polymer matrix and a lithium salt is formed on the surface of the silicon-based electrode active material before battery operation. This coating layer acts as a protective cushion that accommodates volume expansion during charging and discharging, preventing material rupture and maintaining structural integrity throughout cycling, thereby extending cycle life while preserving high energy density
Solution Approach 2:
The electrode structure is designed as a composite material system combining silicon-based active material with a polymer-coating layer containing lithium salt. The polymer matrix provides mechanical flexibility to accommodate volume changes, while the lithium salt reservoir supplies additional lithium ions. This composite structure simultaneously achieves high energy density from silicon and improved cycle life from the protective coating
2Quantity of substance
If silicon-based materials are used to achieve high energy density, then capacity is improved, but volume expansion causes material rupture
Solution Approach 1:
The polymer coating layer is applied beforehand to cushion and accommodate the volume expansion of silicon-based materials during lithiation. This pre-formed protective layer prevents structural rupture while allowing the high-capacity silicon material to undergo necessary volume changes during charging and discharging cycles
Solution Approach 2:
A flexible polymer coating layer is formed on the silicon-based electrode material. This thin film shell provides mechanical compliance that accommodates volume expansion during charging and discharging, preventing material rupture while maintaining structural integrity and enabling high capacity utilization
3Reliability
If conventional electrode materials are used to maintain structural stability, then cycle life is improved, but energy density is limited
Solution Approach 1:
The electrode employs a composite structure combining high-capacity silicon-based materials with a polymer-lithium salt coating layer. This composite design enables the system to achieve high energy density from the silicon core while the polymer coating provides structural stability and extends cycle life, overcoming the limitations of conventional electrode materials
4Quantity of substance
If silicon-based materials are used to achieve high capacity, then energy storage is improved, but volume expansion leads to poor performance
Solution Approach 1:
The polymer coating layer containing lithium salt is formed beforehand on the silicon-based material to cushion volume expansion during charging and discharging. This protective layer maintains structural integrity and ensures consistent electrochemical performance while enabling high energy storage capacity from the silicon-based active material
Solution Approach 2:
The electrode structure is designed as a composite material system where silicon-based materials provide high energy storage capacity while the polymer-lithium salt coating layer ensures reliable performance by accommodating volume changes and maintaining structural stability during cycling
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 lithiated electrode material improves cycle life and rate capability of lithium-ion batteries by supplementing lithium ions during charging and discharging, reducing impedance, and maintaining high coulombic efficiency.
Implementation Method 1
The organic acid lithium salt layer includes an organic acid lithium salt, and the organic acid lithium salt is formed by a lithiation of an organic acid with at least two carboxyl groups
Implementation Method 2
The coating layer includes the lithiated electrode material, an adhesive, and a conductive material
Data Source
AI summary
The present disclosure provides a lithiated electrode material, a preparation method of the lithiated electrode material, and an electrode. The lithiated electrode material includes an electrode active material and an organic acid lithium salt layer. The organic acid lithium salt layer is coated on the surface of the electrode active material. The organic acid lithium salt layer includes an organic acid lithium salt formed by the lithiation of an organic acid with at least two carboxyl groups. The preparation method of the lithiated electrode material includes mixing the electrode active material, the organic acid lithium salt, and a polar solvent to form the lithiated electrode material. The electrode includes a conductive substrate and a coating layer disposed on the conductive substrate. The coating layer includes the lithiated electrode material, an adhesive, and a conductive material.