Non-Aqueous Lithium Cell Electrolyte for High-Temperature Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current power storage elements, such as lithium ion batteries and electrical double layer capacitors, face challenges in achieving high energy density, high output characteristics, and durability, especially at high temperatures, which limits their application in advanced energy storage systems like hybrid electric vehicles and solar power storage.
Innovation Solution
A non-aqueous lithium power storage element is developed, comprising a positive electrode with active carbon and carbon nanotubes, a negative electrode with carbon nanotubes and a dispersing agent, and a lithium salt electrolyte containing LiPF6, LiBF4, and a lithium salt with an imide structure, optimized with specific structural and compositional features to enhance energy density and durability at high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If lithium ion batteries are developed to achieve high output exceeding 3 kW/L, then output characteristic is improved, but energy density reduces to 100 Wh/L or lower and durability deteriorates
Solution Approach 1:
The patent employs a composite electrode structure combining activated carbon (for electrical double layer capacitance) and lithium ion battery materials (for Faraday reaction). This composite approach enables the power storage element to achieve both high output characteristics (3 kW/L or higher) and improved durability by utilizing the complementary strengths of different material systems within a single electrode assembly.
Solution Approach 2:
The invention merges the charge-discharge mechanisms of electrical double layer capacitors and lithium ion batteries into a single power storage element. By integrating non-Faraday reaction (adsorption/desorption) and Faraday reaction (occlusion/release) in the same device, the system achieves both high power output and enhanced durability, resolving the contradiction between output characteristic and reliability.
2Power
If electrical double layer capacitors use activated carbon in electrodes to achieve high output, then output characteristic is improved, but energy density remains no greater than 1 to 5 Wh/L
Solution Approach 1:
The patent uses composite electrode materials combining activated carbon with lithium ion battery active materials. This composite structure enables the device to achieve high output characteristics (0.5 to 1 kW/L from electrical double layer capacitance) while simultaneously increasing energy density beyond the 1 to 5 Wh/L limitation of pure activated carbon capacitors, by adding the energy storage capacity of lithium ion intercalation materials.
3Quantity of substance
If lithium ion batteries are designed for high energy density, then energy density is improved, but output characteristic reduces to 100 Wh/L or lower and durability becomes inferior
Solution Approach 1:
The patent employs composite electrodes containing both activated carbon (providing high power density through electrical double layer capacitance) and lithium ion battery materials (providing high energy density through Faraday reaction). This composite approach enables the power storage element to achieve both high energy density and high output characteristics (3 kW/L or higher), resolving the contradiction between energy density and power output.
4Power
If power storage elements are used to achieve high output, then output characteristic is improved, but high-temperature storage characteristic deteriorates
Solution Approach 1:
The patent introduces a solid electrolyte interface (SEI) layer as an intermediary protective barrier between the electrode and electrolyte. This SEI layer, formed through preliminary electrochemical treatment, acts as a mediator that protects the electrode from degradation at high temperatures while maintaining ionic conductivity, thus improving high-temperature storage characteristics without sacrificing output performance.
Solution Approach 2:
The patent applies preliminary electrochemical treatment to form a stable solid electrolyte interface (SEI) layer before the power storage element is put into service. This preliminary action creates a protective barrier that prevents electrode degradation during high-temperature storage, enabling the device to maintain both high output characteristics and improved high-temperature durability.
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 solution provides a power storage element with improved high-temperature durability and input performance, enabling efficient energy storage and release without the limitations of existing technologies, suitable for advanced energy storage applications.
Implementation Method 1
charge-discharge is accomplished by: non-Faraday reaction by adsorption/desorption of anions similar to an electrical double layer capacitor at about 3 V or higher, at the positive electrode
Implementation Method 2
Faraday reaction by occlusion/release of lithium ions similar to a lithium ion battery, at the negative electrode
Implementation Method 3
a lithium ion-containing non-aqueous electrolyte
Data Source
AI summary
A non-aqueous lithium power storage element that includes a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte, the positive electrode having a positive electrode collector and a positive electrode active material layer that includes active carbon, and the non-aqueous lithium power storage element having configuration (1) and/or (2). (1) The negative electrode includes a negative electrode collector and a negative electrode active material layer (2) The non-aqueous electrolyte contains (A) LiPF6 and/or LiBF4, (B) an imide lithium salt, and (C) an oxalate-complex lithium salt, the ratio of the mass of component (C) to the total mass of components (A) and (B) being 1.0-10.0 mass %.