Lithium Battery Electrolyte Additives for Ni-Rich Cathode Stability

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Solution Overview

Problem

Lithium secondary batteries with high-capacity positive electrodes, such as lamella nickel (Ni)-rich LiNi1-x-yCoxMnyO2 oxide, face rapid degradation due to residual lithium components promoting electrolyte degradation and interfacial reactivity, necessitating an electrochemically and chemically stable film to enhance performance.

Innovation Solution

Incorporation of a positive electrode film additive, 1-(3-((tert-butyldimethylsilyl)oxy)propyl)-5-(4-fluorophenyl)-1H-1,2,3-triazole-4-carbonitrile, and a negative electrode film additive, vinylene carbonate, in the electrolyte to form stable CEI and SEI layers, scavenging acidic components and stabilizing transition metals, thereby reducing degradation and improving ion conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the content of Ni is increased or charge voltage is raised to increase positive electrode capacity, then energy density is improved, but charge/discharge performance degrades rapidly due to electrolyte degradation and interfacial reactivity

Engineering Contradiction:

Improveenergy densityVSAvoidcharge/discharge performance stability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent introduces a fluorinated cyclic carbonate additive as an intermediary substance that mediates between the high-Ni positive electrode and the electrolyte. This additive preferentially reacts with residual lithium components (Li2CO3 and LiOH) on the positive electrode surface to form a stable protective film, preventing direct contact and harmful reactions between the electrolyte and the reactive positive electrode, thus resolving the contradiction between achieving high energy density and maintaining performance stability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies preliminary anti-action by having the fluorinated cyclic carbonate additive preemptively react with residual lithium components on the positive electrode surface during the initial charging cycles. This preliminary reaction forms a stable protective film that prevents subsequent electrolyte degradation and interfacial reactivity, counteracting the harmful effects before they can occur during normal battery operation

Inventive Principle:

Principle #9Preliminary anti-action

2Quantity of substance

If residual lithium components (Li2CO3 and LiOH) are present on the positive electrode, then high capacity is achieved, but electrolyte degradation is promoted and interfacial reactivity increases

Engineering Contradiction:

Improvepositive electrode capacityVSAvoidelectrolyte degradation and interfacial reactivity

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful residual lithium components into a beneficial protective film. The fluorinated cyclic carbonate additive reacts with Li2CO3 and LiOH on the positive electrode surface to form a stable lithium fluoride-containing protective layer. This transforms the originally harmful residual components into a beneficial barrier that protects both the positive electrode and electrolyte from further harmful reactions

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The fluorinated cyclic carbonate acts as a chemical intermediary that facilitates a controlled reaction between residual lithium components and the additive itself, rather than allowing direct harmful reactions between the residual components and the main electrolyte. This intermediary reaction produces a stable protective film that eliminates the harmful effects

Inventive Principle:

Principle #24Intermediary (Mediator)

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 additives form protective films on electrodes, enhancing the lifetime and output characteristics of lithium secondary batteries by reducing resistance and stabilizing nickel content, leading to improved initial cell efficiency, high-temperature performance, and rate capability.

Implementation Method 1

introduction of an additive technique capable of forming an electrochemically and chemically stable film

Methodology Applied

Scientific EffectFilm formation: Deposition (physical)

Implementation Method 2

stabilizing transition metals, thereby reducing degradation

Methodology Applied

Scientific EffectChemical stabilization: Chemical Bonding

Implementation Method 3

The functional additive may further include vinylene carbonate (VC) as a negative electrode film additive

Methodology Applied

Scientific EffectFilm formation: Deposition (physical)

Implementation Method 4

an electrolyte serving as a lithium-ion transmission mediator

Methodology Applied

Scientific EffectIonic conduction: Conduction (electrical)

Implementation Method 5

scavenging acidic components and stabilizing transition metals

Methodology Applied

Scientific EffectChemical scavenging: Chemical Bonding

Data Source

PatentUS12412929B2Electrolyte solution for a lithium secondary battery and a lithium secondary battery including same

Publication Date: 2025.09.09 HYUNDAI MOTOR CO LTD

AI summary

An electrolyte for a lithium secondary battery can enhance lifetime and output characteristics in a high-capacity lithium secondary battery. The electrolyte for a lithium secondary battery includes a lithium salt, a solvent, and a functional additive. The functional additive includes 1-(3-((tert-butyldimethylsilyl)oxy)propyl)-5-(4-fluorophenyl)-1H-1,2,3-triazole-4-carbonitrile as a positive electrode film additive.