Thermal Battery Cathode Using Titanium Sulfide for High-Load Discharge
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thermal batteries with iron disulfide cathode active material do not maintain significant voltage differences during large current discharges, limiting their ability to provide high discharge performance under high load conditions.
Innovation Solution
The use of titanium-containing sulfides as cathode active materials, represented by the formula Ti1-αMαSx, where M is selected from Cr, Mn, Co, Ni, Cu, Zn, Ge, Zr, Nb, Mo, Ag, Cd, Sn, and W, improves reactivity and discharge voltage, allowing for higher voltage maintenance at large current discharges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If iron disulfide composite materials (with IrS2, TiS2, or VS2) are used as cathode active material, then voltage at low current density (0.5 A/cm2) is improved, but voltage at large current density (1 to 2 A/cm2) shows no significant difference compared to iron disulfide alone
Solution Approach 1:
The invention changes the chemical composition parameters of the cathode active material by using titanium-containing sulfide with specific stoichiometric ratios (1.5 ≤ x ≤ 2.75 in Ti1-αMαSx) and controlled doping levels (0 ≤ α ≤ 0.95), which fundamentally alters the material's electrochemical properties to maintain high voltage across all current densities
Solution Approach 2:
The invention employs composite material structure by combining titanium sulfide with dopant elements M (such as Cr, Mn, Co, Ni, Cu, Zn, Ge, Zr, Nb, Mo, Ag, Cd, Sn, or W) to create Ti1-αMαSx compounds that exhibit synergistic effects, achieving both high reactivity and stable voltage output under varying load conditions
2Power
If multiple unit cells are stacked in series to achieve high voltage, then required voltage is obtained, but height of the thermal battery increases
Solution Approach 1:
By changing the electrochemical parameters of the cathode material to achieve higher voltage per unit cell (maintaining 1.6 to 1.8 V or higher at large current densities), the invention reduces the number of unit cells needed in series, thereby decreasing the overall battery height while maintaining required output voltage
3Productivity
If thermal battery is designed for high load operation, then discharge performance under high load is improved, but device size may increase
Solution Approach 1:
The titanium-containing sulfide composite materials provide both high reactivity and stable voltage characteristics, enabling the battery to deliver high power output under large current densities without requiring increased battery size or additional unit cells
Solution Approach 2:
By optimizing the local chemical composition and structure of the cathode active material through controlled doping and stoichiometry, the invention enhances the electrochemical performance at the material level, which translates to improved high-load discharge performance without increasing overall device dimensions
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 approach results in increased discharge voltage and improved high-load discharge performance, enabling thermal batteries to be smaller in size while maintaining excellent discharge characteristics.
Implementation Method 1
a salt molten at the thermal battery operating temperatures
Data Source
AI summary
A thermal battery includes a plurality of unit cells. Each unit cell includes a cathode, an anode, and an electrolyte disposed between the cathode and the anode. The electrolyte includes a salt molten at the thermal battery operating temperatures. The cathode includes a titanium-containing sulfide as an active material.