Lithium Storage Element High Temperature Durability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional power storage systems, such as lithium ion batteries and electric double layer capacitors, face challenges in achieving high energy density, high power characteristics, and durability, especially under high temperature and high load conditions, with existing solutions not effectively addressing energy loss and resistance issues.

Innovation Solution

A nonaqueous lithium-type storage element is developed with a positive electrode containing a lithium compound, optimized with specific concentrations of Na and/or K elements, and a negative electrode capable of intercalating lithium ions, using a nonaqueous electrolytic solution with organic solvents and specific lithium salts, to enhance charging and discharging cycle characteristics and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lithium compound is added to the positive electrode to improve high-temperature durability, then storage durability at high temperature is improved, but energy loss due to voltage reduction increases

Engineering Contradiction:
Improvestorage durability at high temperatureVSAvoidenergy loss due to voltage reduction
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies local quality by adding a lithium compound specifically to the positive electrode rather than uniformly distributing it throughout the battery. This localized addition targets the positive electrode's vulnerability to high-temperature degradation, improving storage durability at high temperature while minimizing the overall impact on energy loss. The lithium compound concentration is optimized at 1-50 wt% of the positive electrode active material to achieve the desired balance between durability improvement and energy loss minimization.

Inventive Principle:
Principle #3Local quality

2Reliability

If the positive electrode contains lithium compound to enhance high-temperature stability, then storage durability is improved, but charging and discharging cycle characteristics under high load deteriorate

Engineering Contradiction:
Improvestorage durability at high temperatureVSAvoidcharging and discharging cycle characteristics under high load
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies parameter changes by precisely controlling the lithium compound concentration within 1-50 wt% of the positive electrode active material. This parameter optimization ensures that the lithium compound provides sufficient high-temperature stability without excessive accumulation that would hinder ion transport. The controlled concentration range allows the positive electrode to maintain both high-temperature durability and acceptable charging/discharging performance under high load conditions.

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If lithium compound is decomposed to reduce voltage reduction, then energy loss is reduced, but resistance increases leading to inferior cycle characteristics

Engineering Contradiction:
Improveenergy loss due to voltage reductionVSAvoidcharging and discharging cycle characteristics
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent applies preliminary action by pre-doping lithium ions into the negative electrode before the battery enters service. This preliminary lithium ion insertion into the negative electrode creates a reservoir that can supply lithium ions during subsequent charging and discharging cycles. As the lithium compound in the positive electrode decomposes and releases lithium ions, the pre-doped negative electrode maintains electrical neutrality and facilitates smooth ion transport, thereby reducing voltage reduction and energy loss while preserving charging/discharging cycle characteristics under high load.

Inventive Principle:
Principle #10Preliminary action

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 significantly reduces energy loss due to voltage reduction under high temperature and high voltage, improves charging and discharging cycle characteristics under high load, and maintains high storage durability, achieving superior I/O characteristics and stability.

Implementation Method 1

non-Faraday reaction based on adsorption/desorption of anions, similar to an electric double layer capacitor, at about 3 V or higher, at the positive electrode

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

Faraday reaction based on occlusion/releasing of lithium ions, similar to a lithium ion battery, at the negative electrode

Methodology Applied
Scientific EffectIntercalation: Absorption (physical)

Implementation Method 3

a lithium compound that decomposes to reduce voltage reduction and enhance durability

Methodology Applied
Scientific EffectDecomposition: Decomposition (biological)

Data Source

PatentEP3736843A1Nonaqueous lithium-type power storage element
Publication Date: 2020.11.11 ASAHI KASEI KOGYO KABUSHIKI KAISHA
  • EP3736843A1 patent drawing
  • EP3736843A1 patent drawing
  • EP3736843A1 patent drawing

AI summary

The invention relates to a method of producing a nonaqueous lithium-type storage element.