Coated Negative Electrode for All-Solid-State Dendrite Control

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Solution Overview

Problem

All-solid-state batteries face issues with lithium dendrite formation leading to solid electrolyte damage and short circuits, as well as uneven stress distribution, which affects their safety and lifespan.

Innovation Solution

A negative electrode with a coating layer comprising ionic conductive polymers and lithiophilic materials is used, which directs lithium dendrite formation between the coating layer and the current collector, reducing stress and enhancing ionic conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pressing force is applied to increase contact area between electrodes and solid electrolyte, then interfacial resistance is reduced, but solid electrolyte layer is damaged by lithium dendrites

Engineering Contradiction:

Improveinterfacial resistanceVSAvoidsolid electrolyte damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A coating layer comprising a polymer and lithiophilic material is introduced as an intermediary between the negative electrode and solid electrolyte. This coating layer serves as a mediator that promotes uniform lithium ion distribution and suppresses lithium dendrite formation, thereby preventing solid electrolyte damage while maintaining low interfacial resistance

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The coating layer is formed using a composite material consisting of a polymer matrix combined with lithiophilic material particles. This composite structure provides both mechanical flexibility and enhanced lithium ion conductivity, enabling the coating to effectively manage lithium deposition while maintaining good contact with the solid electrolyte

Inventive Principle:

Principle #40Composite materials

2Power

If pressing force is applied to increase contact area, then output is improved, but short circuit occurs due to reaction between lithium dendrites and positive electrode

Engineering Contradiction:

ImproveoutputVSAvoidshort circuit prevention

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The coating layer acts as a protective intermediary that controls lithium ion deposition patterns, preventing the formation of protruding lithium dendrites that could bridge to the positive electrode and cause short circuits, while still maintaining sufficient contact area for high power output

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The coating layer is applied in advance to the negative electrode surface to create a protective barrier before lithium deposition occurs. This pre-formed layer cushions and guides lithium ion deposition, preventing harmful dendrite formation before it can occur

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Object-affected harmful factors

If coating layer with lithiophilic material is used to suppress lithium dendrites, then solid electrolyte protection is improved, but ionic conductivity may be reduced

Engineering Contradiction:

Improvesolid electrolyte protectionVSAvoidionic conductivity

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The coating layer uses a composite material where the polymer matrix provides continuous ionic conduction pathways while embedded lithiophilic material particles suppress lithium dendrite formation. This composite structure ensures both protection and high ionic conductivity

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The coating layer distributes lithiophilic material particles locally within the polymer matrix, creating regions with enhanced lithium ion affinity that guide uniform deposition without blocking overall ionic transport. The local concentration of lithiophilic material provides protection while the polymer matrix maintains bulk ionic conductivity

Inventive Principle:

Principle #3Local quality

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 prevents solid electrolyte damage, reduces short circuit occurrences, and improves the safety and performance of all-solid-state batteries by uniformly distributing stress and enhancing lithium ion transfer.

Implementation Method 1

the coating layer has ionic conductivity and electrical conductivity

Methodology Applied

Scientific EffectIonic conductivity: Conduction (electrical)

Implementation Method 2

the coating layer includes a lithiophilic material

Methodology Applied

Scientific EffectLithiophilic interaction: Adsorption

Data Source

PatentUS20230378531A1Negative electrode for all-solid-state battery and all-solid-state battery including the same

Publication Date: 2023.11.23 SIGVARIS AG

AI summary

A negative electrode for all-solid-state batteries and an all-solid-state battery including the same are provided. The negative electrode includes a coating layer disposed on a surface of a negative electrode current collector, the coating layer having ionic conductivity and electrical conductivity, and is configured such that lithium dendrites are formed between the coating layer and the negative electrode current collector, thereby preventing microscopic short circuit.