Boron-based Polymers for EV Storage
Boron-based polymers such as boron nitride nanotubes are two-dimensional nanomaterials that improve electric vehicle energy storage given their high surface areas, large aspect ratios, and excellent thermal conductivities. Let’s look at how BTS can be used in EV storage.
This is a hot topic as demand for electric vehicles continues to rise from 2021 to 2028; the global electric vehicle market is expected to increase at a CAGR of 24.3%, from 287 billion in 2021 to over 1.3 trillion by 2020. Presently polymer nanocomposites are used to insulate and enhance EV storage.
These nanocomposites improve conductivity. To date, though efficacy is too low for practical applications, now researchers from Penn State University are proposing a novel approach based on a combination of polymer nanocomposites and boron nitride nanotubes, or BNNTs. By introducing BNNTS into the polymers, the electrical conduction of the composites can be effectively suppressed while keeping the high dielectric property of the nanotubes.
This strategy can help in designing advanced dielectric materials for energy storage.
How are BNNTs fabricated for Combination with Polymer Nano Composites?
Epitaxial growth of boron nitride nanosheets by chemical vapor deposition is one way but is challenging because the precursors must be separated into two parts.
The precursor should be kept away from the substrate during the process. In preparing polymer dialectics in the laboratory, BNNTs are mostly prepared via top-down methods, that is, mechanical and chemical exfoliation. Exfoliated boron nanotube sheets can be produced by ball milling vortex, fluid exfoliation, and hydrothermal exfoliation.
The sheets are then incorporated into polymer matrices for improved dielectric and thermal performance.
How do Boron Nitride Nanotube Properties Change for Compatibility?
Research has explored surface modifications to improve the interface compatibility between polymers and boron nitride nanotubes. However, there are mismatches in physical and chemical characteristics between the organic-inorganic phases.
Huang and coworkers in the research have improved compatibility via two methods. The non-covalent functionalization using octadecyl amens or ODAs and covalent modification using hyperbranched aromatic polyamides or HBPs. They found that the HBPs modified BNNTs showed stronger interactions with the epoxide resins and increased mechanical properties compared to the unmodified or ODAs modified BNNTs.
Boron Nitride Nanotubes in Nano Composite Films for Electrical Conductivity.
Nanocomposite films containing boron nitride nanotubes are another area of research. They exhibit higher permittivity than pure polymer films due to the high dielectric constant. In addition, this increases the electrical conductivity of the resulting nanocomposite film.
The boron nitride nanoparticles are also used in lubrication, friction reduction, wear resistance, and thermal management. As we can see, dispersing these nanoparticles into polymer matrices is challenging. So to date, their use in polymer matrices has been limited. But research is looking at using electro-spinning technology to create a new polymer composite that shows excellent thermal conductivity and mechanical proper.
These composites may also be used in various devices, including microelectronics, batteries, and other electronic components. In conclusion, research shows BNNTs and polymer composites have an exciting future, but there continue to be limitations. BNNTs bring a wide band gap, high breakdown field, high dielectric constants, and excellent mechanical properties, making them ideal for high-temperature applications.
The benefits of combining these BTS with polymer composites include enhanced dialectical properties and breakdown strengths. But the barriers to commercial production exist in EV storage, including the cost of using liquid exfoliation and the currently low production level that can be achieved.