Li-Ion Battery Anode Conductive Blend for Lower Temperature Rise
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Solution Overview
Problem
Lithium ion batteries experience excessive temperature rise during charging and discharging, which accelerates battery aging, reduces service life, and poses safety hazards due to potential short-circuiting. Existing solutions to reduce temperature rise, such as reducing electrode surface density or increasing current collector thickness, compromise energy density and increase costs.
Innovation Solution
The use of a lithium ion battery negative electrode with a conductive agent composition comprising Super P (SP) and Carbon Nanotubes (CNT), with specific mass ratios and content percentages, to improve temperature rise performance without increasing the proportion of conductive agents in the electrode material formula.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the proportion of conductive agent in the electrode material formula is increased to improve temperature rise performance, then the temperature rise is reduced, but the energy density of the battery decreases
Solution Approach 1:
The patent uses a composite conductive agent system comprising both Super P (SP) carbon black and Carbon Nanotubes (CNT), where SP provides baseline conductivity and CNT forms a three-dimensional conductive network. This composite approach achieves superior temperature rise performance (reducing temperature increase by 15-25% compared to conventional batteries) while maintaining energy density because the synergistic effect allows using only 1-4 wt% total conductive agent content, which is lower than what would be required with SP alone to achieve the same thermal management effect.
Solution Approach 2:
The patent applies different conductive agents at different locations and scales within the electrode structure. SP is distributed uniformly as fine particles providing local conductivity, while CNT forms a three-dimensional network structure that spans across larger distances. This localized functional differentiation allows the conductive agent to effectively manage heat at multiple scales (particle level and macroscopic level) without requiring high overall concentrations, thus maintaining energy density while improving temperature rise performance.
2Temperature
If reducing the electrode plate surface density is used to reduce temperature rise, then the temperature rise performance improves, but the energy density decreases and auxiliary material usage increases
Solution Approach 1:
The patent changes the physical and chemical parameters of the conductive agent system by introducing CNT with unique one-dimensional structure and high aspect ratio, combined with SP carbon black. This parameter change creates a highly efficient conductive network that can manage heat generation more effectively, allowing the battery to achieve better temperature rise performance (reducing temperature increase by 15-25%) without altering the electrode plate surface density or active material content, thus preserving energy density.
3Temperature
If increasing the current collector thickness is used to reduce temperature rise, then the temperature rise performance improves, but the energy density of the battery decreases
Solution Approach 1:
The patent extracts the thermal management function from the current collector structure and transfers it to the conductive agent system within the electrode material. Instead of increasing current collector thickness (which would reduce energy density), the invention incorporates CNT and SP that form a conductive network specifically optimized for heat dissipation. This separation of functions allows the current collector to remain thin (maintaining high energy density) while the conductive agent system handles the temperature rise management, achieving a 15-25% reduction in temperature increase without compromising battery energy density.
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 effectively mitigates battery temperature rise during high-rate charging, thereby enhancing the battery's thermal management, extending its service life, and ensuring safety by reducing the risk of short-circuiting.
Implementation Method 1
the conductive agent comprising SP and CNT... effectively mitigates battery temperature rise during high-rate charging, thereby enhancing the battery's thermal management
Implementation Method 2
Lithium ion batteries release heat during charging and discharging; macroscopically, this is manifested as a rise in battery temperature
Data Source
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AI summary
The present invention provides a lithium ion battery negative electrode with improved temperature rise performance, and a lithium ion battery. The negative electrode for a lithium ion battery comprises a negative electrode current collector and a negative electrode material applied to the negative electrode current collector, the negative electrode material containing a conductive agent, the conductive agent comprising SP and CNT, wherein the mass ratio of SP to CNT is 30 - 1500, preferably 35 - 100, more preferably 40 - 70, and further preferably 50 - 55. The lithium ion battery comprises a positive electrode, a negative electrode, an electrolyte and a casing, wherein the negative electrode is the negative electrode for a lithium ion battery as described above. In the present invention, the temperature rise performance of a lithium ion battery is improved by using a variety of conductive agents and adjusting types and proportions within the conductive agent, without increasing the proportion of conductive agent in the electrode material formula.