Solid-State Battery Electrode Composition for Low-Resistance Binding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium ion secondary batteries face safety concerns due to liquid leakage and potential short-circuits from organic electrolytic solutions, necessitating improved safety and reliability, which existing technologies have not adequately addressed.
Innovation Solution
An electrode composition comprising an inorganic solid electrolyte, an active material, and a binder with specific adsorption and distribution rates, forming an electrode active material layer that enhances discharge capacity and reduces resistance in all-solid state secondary batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a binder is used to improve binding properties between solid particles in an electrode active material layer, then binding properties are improved, but the binder coats the inorganic solid electrolyte and interrupts ion conduction, increasing resistance
Solution Approach 1:
The binder is applied selectively to specific regions or surfaces within the electrode active material layer, ensuring that binding properties are improved only where necessary while leaving other regions free for optimal ion conduction. This localized application prevents the binder from coating all inorganic solid electrolyte particles, thereby maintaining ion conduction pathways.
Solution Approach 2:
An intermediary substance or surface treatment is introduced between the binder and the inorganic solid electrolyte to prevent direct coating. This intermediary layer allows the binder to fulfill its binding function while preventing it from interrupting ion conduction in the solid electrolyte, thus resolving the contradiction between binding strength and ion conduction reliability.
2Strength
If the binder distribution rate to active material is increased to improve binding, then binding properties are enhanced, but ion conduction pathways may be blocked, increasing resistance
Solution Approach 1:
The distribution rate of the binder to active material is optimized to specific parameter ranges that maximize binding properties while minimizing resistance. By carefully controlling the binder concentration, particle size, and distribution uniformity, the invention achieves high binding strength without blocking ion conduction pathways, thus resolving the contradiction between binding enhancement and resistance reduction.
Solution Approach 2:
The binder is applied at a controlled partial distribution rate rather than uniformly across all components. This partial action ensures that sufficient binder is present to improve binding properties between solid particles, while avoiding excessive binder that would coat inorganic solid electrolyte and increase resistance, thereby balancing binding enhancement with resistance control.
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 electrode composition achieves a high discharge capacity and low resistance in all-solid state secondary batteries by optimizing the binder's adsorption and distribution rates, improving binding properties and ion conductivity.
Implementation Method 1
an adsorption rate A of the binder to the active material and an adsorption rate B of the binder to the inorganic solid electrolyte satisfy the following Expressions I) and II)
Data Source
AI summary
Provided are an electrode composition, an electrode sheet for an all-solid state secondary battery, an all-solid state secondary battery, and respective methods of manufacturing the electrode composition, the electrode sheet for an all-solid state secondary battery, and the all-solid state secondary battery. The electrode composition includes: an inorganic solid electrolyte; an active material; and a distributing component that binds to the inorganic solid electrolyte and the active material, in which one kind of the distributing component is a binder, an adsorption rate A of the binder to the active material and an adsorption rate B of the binder to the inorganic solid electrolyte satisfy the following Expressions I) and II), and a distribution rate of the distributing component to the active material in an electrode active material layer formed of the electrode composition exceeds 50%.Adsorption Rate A≥20% Expression I)Adsorption Rate A>Adsorption Rate B Expression II)