Three-Phase Positive Electrode Layer for Low-Temperature Solid-State Sintering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing all-solid-state batteries face challenges in increasing capacity and output due to limitations in the positive electrode layer, particularly when using garnet-type solid electrolytes, which can react with positive electrode active materials at high sintering temperatures, leading to decreased performance.
Innovation Solution
A positive electrode layer for all-solid-state batteries is designed with a three-phase structure, including a first phase with a positive electrode active material containing Li, a second phase with a garnet-type solid electrolyte containing Li, Bi, M2, and O, and a third phase comprising a Li—Bi-M2-O-based compound. This configuration promotes improved sintering and increased density of the positive electrode layer, enhancing the interface between the positive electrode active material and the solid electrolyte.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high sintering temperature is used to increase density and improve sintering of the positive electrode layer, then the density and sintering quality improve, but the garnet-type solid electrolyte reacts with the positive electrode active material, leading to decreased battery performance
Solution Approach 1:
The patent applies parameter changes by precisely controlling the sintering temperature to be below 900°C, which prevents the harmful reaction between the garnet-type solid electrolyte and positive electrode active material while still achieving adequate sintering quality and density for functional performance
Solution Approach 2:
The patent employs composite materials by formulating a positive electrode layer containing multiple phases including the positive electrode active material phase, the garnet-type solid electrolyte phase, and a third phase with specific composition ratios, creating a composite structure that achieves both good sintering quality and high battery performance without requiring high temperatures that would cause material degradation
2Productivity
If conventional positive electrode layer design is used, then manufacturing is simpler, but the capacity and output of the all-solid-state battery are limited
Solution Approach 1:
The patent applies segmentation by dividing the positive electrode layer into three distinct phases with different functions: the first phase provides electrochemical activity, the second phase provides ionic conductivity, and the third phase enhances sintering and structural integrity. This segmented approach enables high capacity and output while maintaining manufacturability through defined composition ratios for each phase
Solution Approach 2:
The patent implements multi-functionality by designing the third phase to simultaneously serve multiple purposes: improving sintering behavior, increasing overall density, enhancing structural stability, and facilitating better interfaces between the active material and solid electrolyte phases, thereby achieving high productivity without proportionally increasing complexity
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 three-phase positive electrode layer design effectively increases the capacity and output of all-solid-state batteries by improving the density and conductivity of the positive electrode layer, while also enhancing the charge/discharge characteristics, particularly at around 3 V.
Implementation Method 1
The positive electrode layer can be manufactured by sintering a positive electrode forming material at a sintering temperature less than 900° C.
Data Source
AI summary
A positive electrode layer for an all-solid-state battery, includes a first phase including a positive electrode active material containing Li, a second phase including a garnet-type solid electrolyte containing Li, Bi, M2, and O, and a third phase different from the first phase and the second phase. The third phase includes a Li—Bi-M2-O-based compound containing Li, Bi, M2, and O, and M2 is at least one element selected from the group consisting of Ca, Sr, Ba, Mg, Y, and Rb.