Lithium Battery Electrolyte Additives for Stable High-Temperature Storage

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Solution Overview

Problem

Rechargeable lithium batteries face issues with gas generation and resistance increase during high-temperature storage, as well as compromised cycle-life characteristics.

Innovation Solution

An electrolyte comprising a non-aqueous organic solvent, a lithium salt, and an additive including a first compound represented by Chemical Formula 1 and a borate-based lithium salt compound, which forms stable films on electrode surfaces to suppress gas generation and resistance, and enhances charge/discharge performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional electrolytes are used in rechargeable lithium batteries, then basic battery operation is maintained, but gas generation and resistance increase occur during high-temperature storage

Engineering Contradiction:
Improvehigh-temperature storage stabilityVSAvoidgas generation and resistance increase
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a fluorinated cyclic carbonate compound as an intermediary substance in the electrolyte that mediates between the electrode and conventional electrolyte components. This compound forms a protective interface layer that prevents harmful reactions and suppresses gas generation during high-temperature storage, while maintaining basic electrolyte functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite electrolyte system by combining fluorinated cyclic carbonate compound with conventional cyclic and chain carbonate solvents. This composite approach leverages the stability benefits of fluorinated compounds while retaining the ionic conductivity advantages of traditional electrolyte components, achieving both high-temperature stability and low gas generation.

Inventive Principle:
Principle #40Composite materials

2Duration of action of stationary object

If conventional electrolytes are used in rechargeable lithium batteries, then charge/discharge operation is maintained, but cycle-life characteristics are compromised

Engineering Contradiction:
Improvecycle-life characteristicsVSAvoidperformance consistency over cycles
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The fluorinated cyclic carbonate compound performs preliminary protective action by forming a stable surface film on electrodes during initial cycles. This pre-formed protective layer prevents subsequent degradation reactions and maintains performance consistency throughout the battery's operational life, extending cycle-life characteristics.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent modifies the chemical composition parameters of the electrolyte by incorporating fluorinated cyclic carbonate compound. This parameter change alters the electrochemical stability window and surface interaction properties, resulting in improved cycle-life characteristics and more consistent performance over repeated charge/discharge cycles.

Inventive Principle:
Principle #35Parameter changes

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 electrolyte effectively reduces gas generation and resistance increase, improving the cycle-life characteristics of rechargeable lithium batteries.

Implementation Method 1

a borate-based lithium salt compound, which forms stable films on electrode surfaces to suppress gas generation and resistance

Methodology Applied
Scientific EffectFilm formation: Deposition (physical)

Implementation Method 2

Both the positive and negative electrodes include an active material in which intercalation and deintercalation of lithium ions are possible... the rechargeable lithium battery generates electrical energy caused by oxidation and reduction reactions

Methodology Applied
Scientific EffectElectrochemical reaction: Redox Reactions

Implementation Method 3

Both the positive and negative electrodes include an active material in which intercalation and deintercalation of lithium ions are possible

Methodology Applied
Scientific EffectIntercalation: Absorption (physical)

Implementation Method 4

the electrolyte... serves as a medium for transmitting ions that participate in an electrochemical reaction of the battery

Methodology Applied
Scientific EffectIon transport: Diffusion

Data Source

PatentEP4700865A1Electrolyte for rechargeable lithium battery and rechargeable lithium battery including the same
Publication Date: 2026.02.25 SAMSUNG SDI CO LTD
  • EP4700865A1 patent drawingFigure 1
  • EP4700865A1 patent drawingFigure 2
  • EP4700865A1 patent drawingFigure 3

AI summary

Electrolytes and rechargeable lithium batteries are provided. The electrolytes comprise a non-aqueous organic solvent, a lithium salt, and an additive. The additive comprises a first compound represented by Chemical Formula 1, and a borate-based lithium salt compound. A detailed description of Chemical Formula 1 is as disclosed in the specification.