Expanded Graphite Negative Electrode with Phase Change Material
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing Li-ion batteries face safety performance issues due to increased internal impedance and decreased energy and power performance when attempting to enhance safety through additive use or complex processes, necessitating a new negative electrode material for improved safety and performance.
Innovation Solution
A negative electrode material comprising expanded graphite intercalated with an organic phase change material, such as paraffin or cerotic acid, which absorbs heat and improves adhesion, reducing internal impedance and enhancing safety by forming a porous carbonization layer and blocking thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additives are added or complicated processes are used to improve safety performance, then safety performance is improved, but electrical performance deteriorates significantly and internal impedance increases
Solution Approach 1:
The organic phase change material is intercalated into the layered structure of expanded graphite, with the guest material nested within the host structure. This nesting approach allows the phase change material to be integrated within the graphite framework, providing safety functions without significantly affecting the overall electrode structure and electrical performance.
Solution Approach 2:
The invention creates a composite material system combining expanded graphite with organic phase change material (such as paraffin, cerotic acid, or polyethylene wax). This composite structure leverages the high conductivity and structural stability of graphite while incorporating the thermal response properties of the organic phase change material, achieving both electrical performance and safety improvement.
2Reliability
If additives are added or complicated processes are used to improve safety performance, then safety performance is improved, but energy density and power performance decrease
Solution Approach 1:
By nesting the organic phase change material within the expanded graphite structure, the invention achieves safety functionality without adding separate additive components that would consume valuable electrode volume. The intercalated structure maximizes space utilization, maintaining high energy density while providing thermal safety responses.
Solution Approach 2:
The expanded graphite host structure serves multiple functions simultaneously: it provides electrical conductivity, maintains structural integrity, enables Li-ion intercalation/deintercalation, and houses the organic phase change material for thermal safety. This multi-functionality eliminates the need for separate safety additives, preserving energy density.
3Reliability
If organic phase change material is intercalated into expanded graphite, then heat storage capacity and safety performance are improved, but manufacturing complexity increases
Solution Approach 1:
The organic phase change material is intercalated into the expanded graphite structure during the electrode preparation process, before battery assembly. This preliminary action ensures that the phase change material is already in position within the graphite layers, eliminating the need for subsequent complex modification steps and simplifying the overall manufacturing process.
Solution Approach 2:
The invention combines the material preparation and safety functionality integration into a single unified process. The organic phase change material is incorporated during the standard electrode manufacturing process, merging what could be separate steps into one operation, thereby reducing manufacturing complexity.
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
The organic phase change material within the expanded graphite enhances heat storage capacity and safety performance by absorbing latent heat, preventing thermal runaway and maintaining electrical performance, while maintaining structural stability and conductivity.
Implementation Method 1
an organic phase change material intercalated into the expanded graphite... the organic phase change material absorbs heat by phase change
Implementation Method 2
the organic phase change material absorbs latent heat, improving the flame retardance
Implementation Method 3
forming a porous carbonization layer and blocking thermal runaway
Implementation Method 4
the organic phase change material has certain viscosity and flexibility, which can improve the adhesion performance of the negative material on the current collector
Data Source
AI summary
The present application relates to a negative electrode material for a secondary battery. The negative electrode material includes an expanded graphite and an organic phase change material intercalated into the expanded graphite. The present application further relates to a method for preparing the negative electrode material and a secondary battery using the negative electrode material. Since the organic phase change material is intercalated into the expanded graphite, when an internal temperature of the secondary battery increases, the organic phase change material absorbs heat by phase change, which can improve the heat storage and energy storage capacity and the safety performance of the secondary battery. In addition, since the organic phase change material has certain viscosity and flexibility, the adhesion performance of the negative electrode material on the current collector can also be improved.