Artificial SEI Transplantation for Aqueous Li-Ion Anodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion insertion anodes in aqueous lithium battery technology are degraded by water, and no solid-electrolyte interphase (SEI) currently exists that enables stable cycling in the presence of water in the electrolyte.
Innovation Solution
A method is developed to form a pre-formed solid electrolyte interphase (SEI) on a lithium-ion insertion electrode by performing multiple charge/discharge cycles in a first cell using an SEI formation electrolyte containing lithium salts like LiFSI and ionic liquids with specific cations and anions, which is then transplanted to a second Li-ion cell with a water-containing electrolyte.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a lithium-ion insertion anode is used in aqueous electrolyte, then the battery can utilize water as electrolyte, but the anode is degraded by water
Solution Approach 1:
The patent applies preliminary action by pre-forming a protective solid-electrolyte interphase (SEI) layer on the lithium-ion insertion anode before exposing it to aqueous electrolyte. This is achieved by performing multiple charge/discharge cycles in a first cell with non-aqueous electrolyte to create the SEI layer, which then protects the anode when transferred to the aqueous electrolyte environment.
Solution Approach 2:
The patent uses an intermediary approach by introducing a solid-electrolyte interphase (SEI) layer as a protective barrier between the lithium-ion insertion anode and the aqueous electrolyte. This SEI layer, formed from specific lithium salts (LiFSI, LiTFSI, LiDCA) and ionic liquids, acts as a mediator that allows the anode to function in aqueous environment without direct water contact.
2Adaptability or versatility
If common organic electrolytes are used with water present, then the electrolyte can be flexible, but cell failure occurs
Solution Approach 1:
The patent applies local quality by creating a specific protective environment around the anode through the SEI layer, while the bulk electrolyte can be aqueous. The SEI layer has different chemical properties (formed from ionic liquids and lithium salts) than the bulk aqueous electrolyte, providing localized protection where it is most needed at the electrode interface.
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 formed SEI protects the anode from water, enabling stable electrochemical performance and improved lithium-ion conductivity, allowing the anode to function effectively in a wet electrolyte with high water content.
Implementation Method 1
SEIs will also provide a protective layer, stabilizing the electrode against corrosion or other undesired side reactions
Implementation Method 2
forming an SEI on a lithium-ion insertion electrode by performing multiple charge/discharge cycles on the electrode in a first cell having an SEI formation electrolyte
Data Source
AI summary
An insertion anode for a Li-ion cell, protected with an SEI by pre-treatment in an SEI-formation cell, is stable for cell cycling even in the presence of substantial water in the cell electrolyte. A method for making the protected anode includes forming an SEI on a lithium-ion insertion electrode by performing multiple charge/discharge cycles on the electrode in a first cell having an SEI formation electrolyte to produce the protected anode. The SEI formation electrolyte includes an ionic liquid having at least one of twelve organic cations.