Solid-State Battery Anode Layer Using Molten Salt to Limit Resistance
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Solution Overview
Problem
The sulfide solid electrolyte in all solid state batteries reacts with the anode current collector, leading to sulfurization and increased internal resistance, which deteriorates battery performance over time.
Innovation Solution
Incorporating a molten salt with a melting point between 30°C and 80°C into the anode active material layer, which acts as a sacrificial material to protect the anode current collector from sulfidation, thereby suppressing the increase in internal resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a sulfide solid electrolyte is used in the anode active material layer, then high ion conductivity is achieved, but the anode current collector undergoes sulfidation and internal resistance increases
Solution Approach 1:
The patent introduces an intermediary substance (coating layer or barrier material) between the sulfide solid electrolyte and the anode current collector. This intermediary prevents direct contact and chemical reaction between the sulfide solid electrolyte and the metal current collector, thereby suppressing sulfidation and the increase in internal resistance while maintaining high ion conductivity of the sulfide solid electrolyte.
Solution Approach 2:
The patent applies a protective coating layer or barrier material to the anode current collector surface before assembling the battery. This preliminary protective action prevents the sulfide solid electrolyte from reacting with the metal current collector during battery operation, thereby preventing sulfidation and maintaining low internal resistance throughout the battery's service life.
2Power
If the anode current collector is made of reactive metal (Ni, Fe, Cu), then electrical conductivity is maintained, but chemical corrosion occurs due to reaction with sulfide solid electrolyte
Solution Approach 1:
The patent introduces a protective coating layer or barrier material as an intermediary between the reactive metal current collector and the sulfide solid electrolyte. This intermediary maintains the electrical conductivity of the current collector while preventing chemical corrosion from the sulfide solid electrolyte, thereby resolving the contradiction between maintaining power and preventing harmful chemical effects.
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 molten salt effectively inhibits the corrosion of the anode current collector, maintaining low internal resistance and preserving battery performance even after repeated charge and discharge cycles.
Implementation Method 1
the sulfide solid electrolyte reacts with an anode current collector, and the anode current collector may be sulfurized
Implementation Method 2
the molten salt may include an ammonium-based cation... the molten salt acts as a sacrificial material, inhibiting chemical corrosion
Data Source
AI summary
A main object of the present disclosure is to provide an all solid state battery in which increase of internal resistance is suppressed. The present disclosure achieves the object by providing an all solid state battery including a cathode, an anode, and a solid electrolyte layer arranged between the cathode and the anode, wherein: the anode includes an anode active material layer and an anode current collector; the anode active material layer contains an anode active material, a sulfide solid electrolyte, and a molten salt of which melting point is 30° C. or more and 80° C. or less; and the anode current collector is a current collector in which a sulfidation due to the sulfide solid electrolyte occurs.