Lithium Ion Battery Electrolyte Additive for Low-Temperature Performance

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Solution Overview

Problem

Lithium ion secondary batteries face challenges in maintaining high-performance characteristics, particularly low-temperature rate capability, due to decomposition reactions at the electrode-electrolyte interface, which lead to irreversible capacity loss and battery deterioration.

Innovation Solution

A lithium ion secondary battery design incorporating a negative electrode with a mixture of carbon materials such as natural graphite, artificial graphite, non-graphitizable carbon, and graphitizable carbon, combined with an electrolyte solution containing a cyclic disulfonate ester compound and an acid anhydride, which forms a low-resistance film on the electrode surface, enhancing low-temperature rate capability and storage characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional electrolyte solutions are used, then the battery can operate, but decomposition reactions occur at the electrode-electrolyte interface leading to high-resistance film formation and poor low-temperature rate capability

Engineering Contradiction:

Improvelow-temperature rate capabilityVSAvoidelectrolyte decomposition

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces cyclic disulfonate ester compounds as intermediary substances that mediate between the electrode and conventional electrolyte. These compounds preferentially decompose to form protective films that prevent harmful electrolyte decomposition, acting as a buffer layer that improves low-temperature performance while suppressing detrimental reactions.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the chemical composition parameters of the electrolyte by incorporating specific cyclic disulfonate ester compounds with controlled concentrations (0.01-5 wt%). This parameter change alters the decomposition behavior at the electrode interface, forming films with optimized resistance characteristics that enable better low-temperature rate capability.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If protection films are formed on the electrode surface to suppress decomposition, then battery characteristics are improved, but high-resistance films may form that inhibit lithium ion reactions

Engineering Contradiction:

Improvebattery characteristicsVSAvoidirreversible capacity loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent carefully controls the concentration parameters of cyclic disulfonate ester compounds (0.01-5 wt%) to form protection films with optimal thickness and resistance characteristics. This parameter optimization ensures the films are sufficiently protective against decomposition while maintaining adequate lithium ion permeability to prevent excessive capacity loss.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite protective film structure by combining cyclic disulfonate ester decomposition products with components from the conventional electrolyte. This composite film architecture integrates the protective benefits of disulfonate esters with the ionic conductivity of conventional electrolyte components, achieving both protection and permeability.

Inventive Principle:

Principle #40Composite materials

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 proposed battery configuration significantly improves low-temperature rate capability and storage performance by reducing electrolyte decomposition and maintaining capacity, thereby extending battery life and stability.

Implementation Method 1

use of an electrolyte solution containing an additive such as a cyclic disulfonate ester and having a film-forming ability has been proposed

Methodology Applied

Scientific EffectFilm formation: Deposition (physical)

Implementation Method 2

the cyclic disulfonate ester compound and an acid anhydride, which forms a low-resistance film on the electrode surface

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 3

the deintercalation and intercalation reactions of lithium ions are caused at the interface between the electrode and the electrolyte solution

Methodology Applied

Scientific EffectIon transport: Diffusion

Data Source

PatentUS9991561B2Lithium ion secondary battery

Publication Date: 2018.06.05 NEC CORP

AI summary

The present invention provides a lithium ion secondary battery comprising: a positive electrode; a negative electrode comprising a negative electrode active material comprising at least one carbon material selected from the group consisting of a natural graphite, an artificial graphite, a non-graphitizable carbon and a graphitizable carbon; and an electrolyte solution comprising a specific cyclic disulfonate ester compound and an acid anhydride.