Gradient Electrode Structure for Crack-Resistant Solid-State Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solid-state batteries face challenges with cracking in the electrode layer due to volume changes during charge and discharge cycles, which can reduce ionic conduction and battery reliability.
Innovation Solution
The proposed electrode structure for solid-state batteries includes a collector layer and an active material layer with specific concentration gradients for the positive electrode active material and the solid electrolyte, which helps absorb volume changes and reduce stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a solid electrolyte is used in an all-solid-state battery, then safety is improved due to incombustibility, but cracking occurs in the electrode layer during charge-discharge cycles due to volume changes, reducing reliability
Solution Approach 1:
The invention applies local quality by creating a concentration gradient of the solid electrolyte within the active material layer. The solid electrolyte concentration varies from the solid electrolyte layer side toward the collector layer side, with higher concentration near the solid electrolyte layer and lower concentration near the collector layer. This localized variation in composition allows different regions of the electrode to accommodate volume changes differently, reducing overall stress and preventing cracking while maintaining the safety benefits of the solid electrolyte.
Solution Approach 2:
The invention utilizes parameter changes by modifying the concentration of the solid electrolyte as a gradient parameter throughout the active material layer. This concentration gradient serves as a compensatory mechanism that counteracts the stress caused by volume expansion and contraction during lithium ion insertion and extraction. By changing the solid electrolyte concentration parameter spatially, the electrode structure can better accommodate dimensional changes without compromising integrity.
2Reliability
If the concentration of solid electrolyte is increased from the solid electrolyte layer side toward the collector layer side, then stress compensation is improved, but manufacturing precision becomes more difficult to control
Solution Approach 1:
The invention applies preliminary action by pre-establishing the concentration gradient of the solid electrolyte in the active material layer before the battery undergoes charge-discharge cycles. This pre-configured gradient is designed to anticipate and compensate for the volume changes that will occur during operation. By preparing the compensatory structure in advance, the electrode can better handle subsequent volume fluctuations without requiring real-time adjustment, thereby reducing the complexity of controlling the gradient during manufacturing.
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 enhances the reliability of solid-state batteries by minimizing cracking and maintaining effective carrier transportation capabilities during charge-discharge cycles, thereby increasing the operation life of the battery.
Implementation Method 1
the lithium ion conductivity is increased by mixing a material for a solid electrolyte and a material for an electrode active material so as to increase the specific surface area with respect to a microscopic interface between the solid electrolyte and the electrode active material
Implementation Method 2
injection and release of lithium ions occur in accordance with charge and discharge, and, in such an instance, expansion and contraction of the volume of the electrode active material layer occur
Data Source
AI summary
An electrode which is to be applied to a solid-state battery and including a collector layer and an active material layer disposed on the collector layer and including an active material showing a concentration distribution in a layer thickness direction which is, among the directions parallel to the layer thickness, a direction toward the side in contact with the collector layer, wherein the active material layer contains at least any one of a conductive auxiliary agent showing a decreasing concentration gradient in the layer thickness direction and a solid electrolyte showing an increasing concentration gradient in the layer thickness direction.