Preformed SEI Anode Fabrication for Lithium Dendrite Suppression
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Solution Overview
Problem
Lithium-ion batteries face issues with 'mossy' lithium structures and lithium dendrite growth due to large volume changes and high reactivity of Li metal electrodes, leading to reduced cycle efficiency and applications.
Innovation Solution
Forming a solid electrolyte interface (SEI) layer on the anode prior to assembly using multiple non-aqueous liquid electrolyte solutions containing lithium salts in organic solvents, which suppresses dendrite growth and provides mechanical protection, and allows for storage and transportation in non-inert environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If Li metal electrode is used to achieve high energy density, then energy density is improved, but dendrite growth and mossy structure formation occur reducing cycle efficiency
Solution Approach 1:
The patent applies preliminary action by forming the SEI layer on the Li metal electrode surface before the electrode is assembled into the battery cell. This pre-formed protective layer prevents harmful reactions during subsequent cycling while maintaining the high energy density benefits of Li metal, thereby resolving the contradiction between energy density and cycle efficiency
Solution Approach 2:
The SEI layer acts as an intermediary between the Li metal electrode and the electrolyte. This intermediate layer mediates the interaction by providing a stable interface that allows ion transport while preventing direct contact between the reactive Li metal and electrolyte, thus preventing dendrite growth while maintaining high energy density
2Ease of manufacture
If SEI layer is formed inside assembled battery cell, then manufacturing process is simplified, but homogeneous reaction kinetics and lithium plating occur reducing quality
Solution Approach 1:
The SEI layer is formed in advance during electrode manufacturing before cell assembly, rather than forming it inside the assembled cell. This preliminary formation allows for controlled, homogeneous reaction kinetics and prevents lithium plating, achieving both quality SEI formation and simplified manufacturing by eliminating post-assembly formation steps
Solution Approach 2:
The SEI formation process is extracted from the cell assembly process and performed separately during electrode manufacturing. This separation allows the SEI formation to be optimized independently, ensuring high quality SEI layers while simplifying the overall manufacturing process by eliminating the need for formation cycles after cell assembly
3Adaptability or versatility
If raw anode is stored and transported without SEI layer, then storage flexibility is improved, but anode is susceptible to environmental degradation
Solution Approach 1:
The SEI layer is formed in advance on the raw anode before storage and transportation. This pre-formed protective layer shields the reactive Li metal from environmental factors such as moisture and oxygen, enabling the anode to be stored and transported in non-inert environments without degradation, thus achieving both storage flexibility and environmental protection
4Manufacturing precision
If multiple SEI-generating electrolytes are applied sequentially, then SEI layer quality is improved, but manufacturing complexity increases
Solution Approach 1:
The SEI formation process is segmented into multiple sequential steps, each using a different SEI-generating electrolyte. This segmentation allows each electrolyte to contribute specific properties to the SEI layer, creating a multi-layered structure with superior quality that combines the benefits of different electrolyte compositions while maintaining manageable manufacturing complexity
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 SEI layer effectively prevents dendrite growth and 'mossy' structure formation, enhancing cycle efficiency and mechanical protection, thereby improving the performance and reliability of lithium-ion batteries.
Implementation Method 1
forming a solid electrolyte interface (SEI) layer on the anode prior to assembly using multiple non-aqueous liquid electrolyte solutions containing lithium salts in organic solvents
Implementation Method 2
non-aqueous liquid electrolyte solutions containing lithium salts in organic solvents
Data Source
AI summary
A method for fabricating an anode for a lithium ion battery cell is described and includes forming a solid electrolyte interface (SEI) layer on a raw anode prior to assembly into a battery cell by applying a first SEI-generating electrolyte to the raw anode to form a first intermediate anode, applying a second SEI-generating electrolyte to the first intermediate anode to form a second intermediate anode, and applying a third SEI-generating electrolyte to the second intermediate anode to form a cell anode, wherein the cell anode includes the raw anode having the SEI layer. Thus, a cell anode is formed by sequentially applying SEI-generating electrolytes to a raw anode to form the cell anode with an SEI layer, and a lithium ion battery cell is formed by assembling the cell anode into a cell pack, with a cathode, and a separator, and adding a cell electrolyte prior to sealing.