Stacked Solid-State Battery with Doped Electrolyte for High-Rate Performance
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Solution Overview
Problem
Stacked all-solid-state batteries with solid electrolytes face challenges in achieving high charge/discharge rates due to large electrical resistance at the electrode-electrolyte interface, leading to capacity loss and inefficiency.
Innovation Solution
The use of a specific solid electrolyte composition, Li7-x-yLa3Zr2-x-yM1xM2yO12, with M1 and M2 selected from Nb, Sb, and W, and a NASICON-type crystal structure, along with a lithium-containing phosphate compound, to enhance ion conductivity and reduce internal resistance, combined with an internal current collecting layer to improve electron transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a stacked battery configuration is used to increase battery capacity per unit volume, then the energy density is improved, but the charge/discharge rate performance deteriorates due to large electrical resistance at the electrode-solid electrolyte interface
Solution Approach 1:
The patent modifies the chemical composition parameters of the solid electrolyte by incorporating specific dopants (Nb, Sb, Ta, or W) at controlled concentrations (0.01-5.0 wt%) into the Li7La3Zr2O12 base structure. This parameter change optimizes the electrical conductivity of the solid electrolyte, reducing interfacial resistance and enabling higher charge/discharge rates while maintaining the stacked battery's high capacity density.
Solution Approach 2:
The patent creates a composite solid electrolyte material by combining Li7La3Zr2O12 with dopant oxides (Nb2O5, Sb2O5, Ta2O5, or WO3) to form a composite structure. This composite material exhibits enhanced electrical conductivity compared to the base material, allowing the stacked battery to achieve both high capacity density and improved charge/discharge rate performance.
2Productivity
If the charge/discharge rate is increased to improve productivity, then the power output is improved, but the battery capacity is lost due to overvoltage and ohmic drop from high electrical resistance
Solution Approach 1:
The patent optimizes the electrical conductivity parameter of the solid electrolyte through controlled doping with Nb, Sb, Ta, or W elements. By adjusting the dopant concentration (0.01-5.0 wt%), the electrical resistance is reduced, minimizing ohmic drops and overvoltage effects during high-rate charge/discharge operations, thereby reducing energy loss while maintaining high productivity.
3Reliability
If a solid electrolyte is used to eliminate organic electrolyte leakage and improve safety, then the safety is improved, but the electrical resistance at the electrode interface increases
Solution Approach 1:
The patent develops a composite solid electrolyte by incorporating dopant oxides (Nb2O5, Sb2O5, Ta2O5, or WO3) into the Li7La3Zr2O12 matrix. This composite structure maintains the inherent safety advantages of solid electrolytes (no leakage, no volatilization) while significantly improving electrical conductivity through the dopant-induced structural modifications and increased charge carrier density.
Solution Approach 2:
The patent modifies the electrical conductivity parameter of the solid electrolyte through chemical doping. By introducing dopant elements at controlled concentrations, the electrical resistance is reduced without compromising the safety characteristics of the solid electrolyte, thus resolving the contradiction between safety and electrical resistance.
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 results in lower internal resistance, improved ion conductivity, and enhanced charge/discharge performance at high rates, increasing the battery's capacity and reliability.
Implementation Method 1
conduction of lithium ions is possible in the solid electrolyte
Implementation Method 2
contains a first solid electrolyte represented by the following composition formula (1): Li7-x-yLa3Zr2-x-yM1xM2yO12
Data Source
AI summary
A stacked solid-state battery according to the present disclosure has a configuration in which a plurality of cells, each including a positive electrode layer, a negative electrode layer, and a solid electrolyte layer provided between the positive electrode layer and the negative electrode layer, are stacked such that the positive electrode layers or the negative electrode layers of adjacent cells are disposed to face each other, contains a first solid electrolyte represented by the following composition formula (1).Li7-x-yLa3Zr2-x-yM1xM2yO12 (1)(In the Formula (1), 0.010≤x≤2.00, 0.010≤y≤1.50, M1 is one element selected from the group consisting of Nb, Sb, Ta, and W and having the highest content in the first solid electrolyte, and M2 is at least one element selected from the group consisting of Nb, Sb, Ta, and W, and is an element other than M1.)