Non-Aqueous Lithium Storage Electrode Composition for Low-Temp Output
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Solution Overview
Problem
Existing non-aqueous lithium-type electricity storage elements face challenges in achieving high energy density and high output while maintaining performance in a wide temperature environment, particularly due to increased internal resistance and lithium dendrite formation at low temperatures.
Innovation Solution
The solution involves a non-aqueous lithium-type electricity storage element with a positive electrode active material layer containing activated carbon and a transition metal oxide, optimized with specific pore structures and additives to enhance lithium ion diffusivity and interaction, allowing for high energy density and output without impairing ion diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the positive electrode active material layer contains only activated carbon with fine pore structure to increase energy density, then the capacity per unit weight increases, but the lithium ion diffusivity is impaired and output characteristic deteriorates
Solution Approach 1:
The patent applies composite materials by combining activated carbon with conductive polymer and/or transition metal oxide in the positive electrode active material layer. This composite structure allows the activated carbon to provide high capacity while the conductive polymer and transition metal oxide components maintain lithium ion diffusivity and electrical conductivity, thereby achieving both high energy density and high output characteristic without sacrificing either property
Solution Approach 2:
The patent applies local quality by creating different functional regions within the positive electrode active material layer. The activated carbon provides high capacity in specific regions, while conductive polymer and transition metal oxide are distributed to ensure lithium ion transport pathways and electrical conductivity in other regions, allowing each component to perform its specialized function optimally
2Quantity of substance
If the positive electrode active material layer is optimized for high energy density with surface modification or fine pore control, then the capacity increases, but the lithium ion diffusion at interface and inside pores is prevented, reducing performance in lowered temperature environment
Solution Approach 1:
The patent applies intermediary by introducing conductive polymer and transition metal oxide as mediating substances between the activated carbon and the electrolyte. These intermediaries facilitate lithium ion transport to and from the activated carbon pores, ensuring that even at low temperatures where diffusion is naturally slower, the lithium ions can still reach the active material effectively, thus maintaining reliability across temperature ranges
Solution Approach 2:
The patent applies parameter changes by modifying the physical and chemical parameters of the positive electrode active material layer, including pore size distribution, surface area, and composition ratios of different materials. These parameter adjustments optimize both the capacity and the lithium ion diffusivity, ensuring high performance across varying temperature conditions
3Productivity
If lithium ion batteries are developed for high output exceeding 3 kW/L, then the output characteristic improves, but the energy density decreases to 100 Wh/L or lower and durability becomes inferior
Solution Approach 1:
The patent applies universality by designing the positive electrode active material layer to perform multiple functions simultaneously: activated carbon provides high capacity for energy density, while conductive polymer and transition metal oxide provide electrical conductivity and lithium ion transport pathways for high output. This multi-functional design allows the same electrode structure to achieve both high energy density and high output characteristic without the trade-off seen in conventional lithium ion batteries
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
This configuration enables the storage element to maintain high energy density and output performance across a wide temperature range, reducing internal resistance and preventing lithium dendrite formation, thus ensuring safety and reliability.
Implementation Method 1
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 intercalation/release of lithium ions similar to a lithium ion battery, at the negative electrode
Implementation Method 3
forming active sites that interact reversibly with Li ions in a positive electrode active material layer, which improves a capacity per unit weight of the positive electrode active material without impairing diffusivity of Li ions inside the positive electrode active material layer
Data Source
AI summary
Provided is a non-aqueous lithium-type electricity storage element which includes a positive electrode current collector having a positive electrode active material layer disposed thereon, wherein, in a solid-state 7Li-NMR spectrum of the positive electrode active material layer, a signal area ratio a/b, which is the ratio of a signal area ratio of component A having a signal at least at −2 to 2.5 ppm to a signal area of component B having a signal at −6 to −2.5 ppm is 1.5 to 20.0.