Lithium-Alloy Negative Electrode for Wide-Temperature Battery Performance
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Solution Overview
Problem
Non-aqueous electrolyte batteries face challenges in maintaining high-temperature storage characteristics and low-temperature load characteristics, as additives like propane sultone and lithium bis(oxalate)borate can interfere with discharge reactions, increasing internal resistance and reducing battery performance.
Innovation Solution
A non-aqueous electrolyte battery design featuring a negative electrode with a lithium layer, a lithium-aluminum alloy layer formed on its surface, and a carbon layer, where the aluminum layer is reacted with the lithium layer to form the alloy, enhancing the battery's storage and load characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an electrolyte contains an additive such as propane sultone or lithium bis(oxalate)borate to suppress the reaction between electrolyte and electrode, then high-temperature storage characteristics are improved, but a coating formed on the electrode surface interferes with the discharge reaction, increasing internal resistance and reducing discharge characteristics
Solution Approach 1:
The patent changes the chemical composition parameters of the electrolyte by specifying precise molar ratios of lithium salts (LiB(C2O4)2 and LiBF4 from 2:8 to 5:5) and solvent components (cyclic carbonate to chain carbonate from 30:70 to 70:30). These parameter adjustments optimize the balance between forming protective coatings for storage stability and maintaining sufficient ionic conductivity for discharge performance, resolving the contradiction between storage characteristics and internal resistance
Solution Approach 2:
The patent employs a composite electrolyte system combining multiple lithium salts (lithium bis(oxalate)borate and lithium tetrafluoroborate) with a mixed solvent system (cyclic carbonate and chain carbonate). This composite approach creates a synergistic effect where different components contribute to both protective film formation and ionic conductivity, simultaneously improving storage characteristics while controlling internal resistance
2Reliability
If the battery is stored at a high temperature, then the reaction between electrolyte and electrode can occur, leading to swelling of the battery, but suppressing this reaction is needed to maintain storage characteristics
Solution Approach 1:
The patent converts the harmful high-temperature reaction between electrolyte and electrode into a beneficial protective film formation process. By carefully controlling the electrolyte composition, the reaction products form stable coating layers on electrode surfaces that prevent further degradation and swelling, thus transforming the harmful thermal reaction into a protective mechanism
Solution Approach 2:
The patent adjusts the molar ratio of lithium salts and solvent composition to control the extent and nature of electrolyte-electrode reactions. These parameter changes ensure that reactions at high temperature produce stable, non-swelling protective layers rather than harmful decomposition products, maintaining battery integrity during storage
3Reliability
If a coating is formed on the electrode surface to suppress the reaction with electrolyte, then storage characteristics are improved, but the discharge characteristics are likely to be reduced after high temperature storage
Solution Approach 1:
The patent optimizes the composition parameters of the electrolyte, specifically the molar ratios of lithium salts and the ratio of cyclic to chain carbonates. These parameter adjustments control the properties of the surface coating formed during storage, ensuring it provides sufficient protection for storage stability while maintaining adequate ionic conductivity for discharge performance
Solution Approach 2:
The patent creates a coating with differentiated properties: it provides high protection quality for storage stability while maintaining sufficient conductivity quality for discharge operations. The electrolyte composition is designed to form a coating that is protective yet permeable, allowing lithium ion transport during discharge while preventing degradation during storage
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 battery exhibits improved high-temperature storage characteristics and low-temperature load characteristics, with the lithium-aluminum alloy layer and carbon layer combination effectively suppressing deterioration and maintaining discharge performance across a wide temperature range.
Implementation Method 1
causing the lithium layer and the aluminum layer to react with each other in order to form the lithium-aluminum alloy layer on the surface of the lithium layer
Data Source
AI summary
The non-aqueous electrolyte battery is excellent in high-temperature storage characteristics and load characteristics at low temperature. A non-aqueous electrolyte battery of the present invention includes a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte. The negative electrode includes a lithium layer, a lithium-aluminum alloy layer formed on a surface of the lithium layer, and a carbon layer on the lithium-aluminum alloy layer. The non-aqueous electrolyte battery of the present invention can be manufactured by a method for manufacturing a non-aqueous electrolyte battery that includes providing an aluminum layer on the surface of the lithium layer to obtain a laminate, forming the carbon layer on a surface of the aluminum layer to obtain a laminate for a negative electrode, and causing the lithium layer and the aluminum layer of the laminate for a negative electrode to react with each other to form the lithium-aluminum alloy layer.