Negative Electrode Additives for Fast-Coated Li-Ion Battery Anodes
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Solution Overview
Problem
The challenge is to enhance the production efficiency of lithium-ion batteries without compromising their discharge capacity, as increasing coating speed often leads to cracking of the active material layer and higher production costs.
Innovation Solution
Incorporating specific additives and metal elements into the negative active material layer, such as stearic acid derivatives and metals like Al, Co, and Cr, which exhibit peaks in infrared spectroscopy within certain wavenumber ranges, to improve flexibility and lithiation performance, while controlling their concentrations and ratios to optimize production efficiency and discharge capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the coating speed of electrodes is increased to improve production efficiency, then the production efficiency is improved, but the temperature of the oven increases and the electrode plate wobbles, leading to cracking of the active material layer and substandard quality
Solution Approach 1:
The patent introduces specific chemical additives (stearic acid and its derivatives) into the electrode slurry to modify the rheological and thermal properties of the active material layer. This changes the material parameters to allow faster coating speeds without causing cracking or excessive oven temperature requirements, thus resolving the contradiction between production efficiency and manufacturing precision
Solution Approach 2:
The additive acts as an intermediary substance between the active material particles and the binder, improving interfacial adhesion and reducing internal stress during drying. This mediator prevents cracking that would otherwise occur at high coating speeds, enabling both high productivity and high quality electrode plates
2Reliability
If the coating weight of the active material layer is reduced to prevent cracking, then the cracking is reduced, but the discharge capacity of the lithium-ion battery decreases
Solution Approach 1:
By modifying the chemical composition through additive incorporation, the patent changes the mechanical and thermal parameters of the active material layer. This allows the coating weight to be increased without causing cracking, thereby maintaining both reliability and quantity (discharge capacity)
Solution Approach 2:
The patent creates a composite structure within the active material layer by incorporating stearic acid derivatives that form a network structure. This composite approach enhances the mechanical strength and thermal stability of the layer, allowing higher coating weights without cracking, thus maintaining both quality and discharge capacity
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 increases production efficiency while maintaining high discharge capacity by reducing cracking risks and enhancing lithiation performance, thereby improving the overall performance and efficiency of lithium-ion batteries.
Implementation Method 1
In an infrared spectroscopy test, the negative active material layer exhibits at least a first peak and a second peak in a wavenumber range of 2500 cm−1 to 3200 cm−1. The first peak corresponds to a wavenumber k1 falling within a range of 2800 cm−1≤k1≤2900 cm−1, the second peak corresponds to a wavenumber k2 falling within a range of 2900 cm−1≤k2≤3000 cm−1
Data Source
AI summary
An electrochemical device includes a negative electrode. The negative electrode includes a negative current collector and a negative active material layer disposed on at least one surface of the negative current collector. In an infrared spectroscopy test, the negative active material layer exhibits at least a first peak and a second peak in a wavenumber range of 2500 cm−1 to 3200 cm−1. This indicates that the negative active material layer contains an additive, and the additive increases the production efficiency of the negative electrode, thereby increasing the production efficiency of the electrochemical device. In addition, the electrochemical device exhibits a high discharge capacity.