Positive Electrode Plate Hyper Branched Polymer Carbon Nanotube Conductivity
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Solution Overview
Problem
Lithium batteries face a trade-off between safety and conductivity due to the introduction of hyper branched polymers, which enhance safety but compromise discharge performance, and conductive powders, which improve conductivity but are not sufficient to compensate for the loss.
Innovation Solution
A positive electrode plate composition comprising hyper branched polymer, carbon nanotubes, and active materials bonded by a coupling agent, with specific weight ratios and reaction conditions to form a conductive network that balances safety and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hyper branched polymer is introduced into the electrode to enhance safety, then the risk of thermal runaway is reduced, but the discharge performance and conductivity of the battery deteriorate
Solution Approach 1:
The patent uses a composite material system consisting of hyper branched polymer as binder, carbon nanotube as conductive additive, and coupling agent to create an integrated electrode structure that simultaneously achieves safety and conductivity. The coupling agent forms chemical bonds between the polymer and carbon nanotube, creating a synergistic composite that overcomes the limitations of individual components.
Solution Approach 2:
The coupling agent acts as an intermediary substance that bridges the hyper branched polymer and carbon nanotube, facilitating strong interfacial bonding. This intermediary enables effective stress transfer and electrical connectivity between the polymer matrix and conductive nanotube network, resolving the contradiction between safety enhancement and conductivity maintenance.
2Power
If conductive powder is doped to improve conductivity, then the electrical conductivity increases, but it cannot compensate for the conductivity loss caused by introducing hyper branched polymer
Solution Approach 1:
The patent changes the形态 and distribution parameters of conductive additives by using carbon nanotube instead of traditional conductive powder. The one-dimensional nanotube structure provides superior electrical pathways compared to zero-dimensional powder, achieving higher conductivity at lower loadings while maintaining the safety benefits of hyper branched polymer.
Solution Approach 2:
The patent transitions from zero-dimensional conductive powder to one-dimensional carbon nanotube, utilizing the dimensional advantage to create efficient three-dimensional conductive networks within the electrode. This dimensional upgrade enables better electrical connectivity without increasing the volume fraction of conductive additives, thus preserving safety properties.
3Power
If carbon nanotube is added to form conductive network, then the electrical properties improve, but the manufacturing complexity and cost increase
Solution Approach 1:
The patent performs preliminary action by pre-functionalizing the carbon nanotube surface and pre-synthesizing the hyper branched polymer with coupling agent groups before electrode fabrication. This preliminary preparation enables direct mixing and bonding during standard electrode manufacturing processes, avoiding the need for additional complex processing steps despite using advanced nanomaterials.
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 solution achieves improved electrical properties and capacitance while maintaining safety, as evidenced by reduced battery impedance and enhanced discharge performance across various discharge rates.
Implementation Method 1
the hyper branched polymer, the carbon nanotube, and the active material are bonded by 0.01 to 1 parts by weight of coupling agent
Implementation Method 2
0.1 to 6 parts by weight of carbon nanotube, wherein the hyper branched polymer, the carbon nanotube, and the active material are bonded by 0.01 to 1 parts by weight of coupling agent
Data Source
AI summary
A method of forming slurry for a positive electrode plate is provided, which includes reacting maleimide compound and barbituric acid to form a hyper branched polymer. 0.1 to 1 part by weight of the hyper branched polymer is mixed with 0.01 to 1 part by weight of coupling agent and 0.1 to 6 parts by weight of carbon nanotube to form a mixture. 80 to 97.79 parts by weight of active material is added to the mixture, wherein the hyper branched polymer, the carbon nanotube, and the active material are bonded by the coupling agent.