Dual Electrolyte Electrode Coating for Low-Resistance Li Batteries
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Solution Overview
Problem
Lithium secondary batteries face issues with increased interfacial resistance, reduced capacity, and stability due to additional decomposition reactions of electrolytes, particularly when overcharged, leading to potential heat generation and ignition.
Innovation Solution
A method of forming both a chemically and mechanically stable organic electrolyte layer and inorganic electrolyte layer on the electrode surface using specific compositions, including compounds represented by Formula 1, to enhance the electrode's performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If only organic electrolyte is used, then ionic conductivity is maintained, but interfacial resistance increases and decomposition reactions occur
Solution Approach 1:
The patent applies composite materials by forming a dual-layer electrolyte structure consisting of an inorganic electrolyte layer (e.g., LiF, Li2SiO3) and an organic electrolyte layer. The inorganic layer provides chemical stability and suppresses decomposition reactions at the electrode interface, while the organic layer maintains ionic conductivity. This composite structure resolves the contradiction between reliability and harmful decomposition effects.
Solution Approach 2:
The inorganic electrolyte layer acts as an intermediary between the electrode and the organic electrolyte. It forms a stable solid electrolyte interphase (SEI) that mediates the interaction, preventing direct contact between the organic electrolyte and electrode, thereby suppressing decomposition reactions while still allowing efficient lithium ion transport.
2Stability of the object's composition
If inorganic electrolyte is used, then chemical stability improves, but interfacial resistance increases
Solution Approach 1:
The patent segments the electrolyte system into two distinct functional layers: an inorganic electrolyte layer for chemical stability and an organic electrolyte layer for low interfacial resistance. This segmentation allows each layer to perform its specialized function without the drawbacks of using a single electrolyte type, resolving the contradiction between chemical stability and interfacial resistance.
Solution Approach 2:
Different regions of the electrolyte system are assigned different properties: the inorganic electrolyte layer near the electrode provides high chemical stability, while the organic electrolyte layer provides low resistance. This local differentiation of qualities allows the system to simultaneously achieve both chemical stability and low interfacial resistance.
3Productivity
If battery is overcharged, then capacity utilization increases, but heat generation and ignition risk increase due to additional decomposition
Solution Approach 1:
The patent applies preliminary action by pre-forming a stable inorganic electrolyte layer on the electrode surface before battery operation. This pre-formed protective layer prevents additional decomposition reactions during overcharging, thereby suppressing heat generation and ignition risks while allowing full capacity utilization.
Solution Approach 2:
The inorganic electrolyte layer serves as a beforehand cushioning layer that absorbs and prevents the propagation of decomposition reactions. During overcharging conditions, this protective layer cushions against the harmful effects of additional decomposition, preventing heat generation and maintaining safety.
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 method reduces interfacial resistance, improves capacity characteristics, and enhances high-temperature stability, ensuring safer battery operation by minimizing decomposition reactions.
Implementation Method 1
forming a first electrolyte layer by immersing an electrode current collector in a composition for forming the first electrolyte layer and applying a current; and forming a second electrolyte layer by immersing the electrode current collector having the first electrolyte layer formed thereon in a composition for forming the second electrolyte layer and applying a current
Data Source
AI summary
The present invention provides a method of preparing an electrode for a lithium secondary battery which includes forming a first electrolyte layer by immersing an electrode current collector in a composition for forming the first electrolyte layer and applying a current, and forming a second electrolyte layer by immersing the electrode current collector having the first electrolyte layer formed thereon in a composition for forming the second electrolyte layer and applying a current, wherein one of the composition for forming the first electrolyte layer and the composition for forming the second electrolyte layer is a composition for forming an organic electrolyte layer, and another one is a composition for forming an inorganic electrolyte layer, and the composition for forming an inorganic electrolyte layer includes a compound represented by Formula 1.