Phosphorus-Stabilized Cathode Layer for Low-Resistance Solid-State Batteries
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Solution Overview
Problem
Conventional all-solid-state batteries suffer from high battery resistance due to oxidation of cathode active material particles and solid electrolyte particles, which affects their performance.
Innovation Solution
A cathode layer for all-solid-state batteries is designed with cathode active material and solid electrolyte particles containing a phosphorus element, coated with a lithium ion conducting oxide, and subjected to vacuum-drying to maintain the phosphorus in an unoxidized state, as indicated by a P peak intensity ratio greater than 0.58 in X-ray photoelectron spectroscopy measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional all-solid-state batteries are used, then the battery structure is simple, but the battery resistance remains high due to oxidation of cathode active material particles and solid electrolyte particles
Solution Approach 1:
A phosphorus-containing compound is introduced as an intermediary substance between the cathode active material particles and solid electrolyte particles. This phosphorus compound forms a protective interface layer that prevents direct contact and oxidation reactions between the cathode active material and solid electrolyte, thereby reducing battery resistance without fundamentally changing the overall battery structure
Solution Approach 2:
The invention changes the chemical composition parameters of the cathode layer by incorporating phosphorus-containing compounds with specific phosphorus-to-metal ratios. By controlling the phosphorus content and its distribution in the cathode layer, the oxidation resistance is enhanced while maintaining manageable structural complexity
2Reliability
If the cathode layer contains phosphorus element with high P peak intensity ratio, then oxidation is suppressed and battery resistance decreases, but the manufacturing precision requirement increases
Solution Approach 1:
The phosphorus-containing compound is pre-synthesized and prepared before being incorporated into the cathode layer. This preliminary preparation ensures that the phosphorus is already in the correct chemical form and concentration, reducing the need for precise in-situ control during battery manufacturing and making it easier to achieve the desired P peak intensity ratio
Solution Approach 2:
The invention uses composite materials approach by combining cathode active material particles, solid electrolyte particles, and phosphorus-containing compounds into a multi-component cathode layer. This composite structure provides oxidation resistance through the phosphorus component while allowing each material to maintain its own processing characteristics, reducing overall manufacturing precision requirements
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 cathode layer significantly reduces battery resistance by suppressing oxidation, thereby enhancing the conductivity and overall performance of the all-solid-state battery.
Implementation Method 1
Conventional all-solid-state batteries suffer from high battery resistance due to oxidation of cathode active material particles and solid electrolyte particles
Implementation Method 2
a lithium ion conducting oxide, the lithium ion conducting oxide coating at least part of the surface of the cathode active material particles
Implementation Method 3
vacuum-drying the cathode active material particles at a temperature of 120° C. or more and 300° C. or less for one hour or more
Data Source
AI summary
Provided is a cathode that is configured to decrease battery resistance when it is used in an all-solid-state battery, and a method for producing the cathode. Disclosed is a cathode comprising a cathode layer for all-solid-state batteries, wherein the cathode layer contains cathode active material particles and solid electrolyte particles; wherein at least one of the cathode active material particles and the solid electrolyte particles contain a phosphorus element; and wherein, in a photoelectron spectrum by X-ray photoelectron spectroscopy measurement of the cathode layer, a P peak intensity ratio (A/B), which is derived from the phosphorus element, of a signal intensity A at a binding energy of 131.6 eV to a signal intensity B at a binding energy of 133.1 eV, is larger than 0.58.