Sn-Sb Sulfide Negative Electrode Material for Lithium Batteries
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Solution Overview
Problem
Conventional lithium secondary batteries face issues such as degradation at high temperatures, Li dendrite formation at low temperatures, and internal short circuits due to the limitations of graphite negative electrodes, which require special facilities and high-temperature processing for alternative materials like Sn—Sb based sulfide glass.
Innovation Solution
A negative electrode active material using Sn—Sb based sulfide with a disordered crystal structure, coated with a lithium-ion occluding component, is manufactured through a method involving alkali metal sulfide addition to a tin and antimony halide solution, eliminating the need for high-temperature processing and special facilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Sn—Sb based sulfide glass is used as negative electrode material, then battery performance (capacity and cycle life) is improved, but manufacturing complexity increases due to requirement of high-temperature glass melting facilities
Solution Approach 1:
The invention changes the manufacturing parameters from high-temperature glass melting (around 1000°C) to room-temperature or low-temperature chemical synthesis methods. This parameter change allows production of Sn—Sb based sulfide without specialized high-temperature facilities, resolving the contradiction between improved cycle life and manufacturing complexity
Solution Approach 2:
The invention replaces expensive, complex glass melting facilities with simple, inexpensive chemical synthesis equipment. By using readily available reagents and standard laboratory equipment instead of specialized high-temperature furnaces, the manufacturing process becomes simpler and more accessible while maintaining product performance
2Quantity of substance
If Sn—Sb based sulfide glass is combined with Si through mechanical milling, then capacity is improved, but manufacturing cost and process complexity increase
Solution Approach 1:
The invention merges the synthesis of Sn—Sb based sulfide and Si into a single chemical reaction process. By co-precipitating both components from solution, the invention eliminates the need for separate mechanical milling steps to combine them, thereby maintaining high capacity while simplifying the manufacturing process and reducing costs
Solution Approach 2:
The invention uses chemical precipitation as an intermediary process to combine Sn—Sb based sulfide and Si particles. Instead of mechanical milling, the chemical synthesis process simultaneously produces and integrates both components in the desired size range, making the manufacturing process easier and more efficient
3Ease of manufacture
If graphite negative electrode is used, then manufacturing simplicity is maintained, but battery performance is limited and safety issues occur at high temperatures
Solution Approach 1:
The invention uses Sn—Sb based sulfide as a composite negative electrode material that combines the benefits of high capacity with improved stability. The specific composition and structure of this composite material provide better high-temperature performance compared to graphite, while still allowing for relatively simple manufacturing processes
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 enhances battery safety by reducing heat generation in internal short circuits and achieves stable cycle life and high capacity without the need for expensive glass melting methods, while maintaining performance comparable to Sn—Sb based sulfide glass.
Implementation Method 1
adding alkali metal sulfide to a mixed solution of tin halide and antimony halide
Data Source
AI summary
The teachings herein are directed at a lithium secondary battery negative electrode active material consisting of a Sn Sb based sulfide that delivers a high electrode capacity density, excellent output characteristics, and excellent cycle life characteristics and also provide a method for manufacturing the lithium secondary battery negative electrode active material, said method being capable of easily manufacturing the high performance lithium secondary battery negative electrode active material at low cost without requiring a high-temperature processing step and special facilities as required in a glass melting method. The negative electrode active material preferably is prepared using a method that includes a step of obtaining a Sn Sb based sulfide precipitate by adding an alkali metal sulfide to a mixed solution of a tin halide and an antimony halide.