By Shane Lauth, Senior Product Manager, Heat Shrink Tubing, and John Sandwell, Senior Product Manager, EMI Shielding, TE Connectivity
This transformation brings unprecedented challenges and opportunities for high-voltage (HV) component protection, which is pivotal in ensuring safety, reliability, and performance in next-gen EV and electrical/electronic (E/E) architectures. Gone are the days when specifications for heat shrink tubing and electromagnetic interference (EMI) shielding could be addressed late in development cycles. Doing so now risks costly redesigns, space limitations, or compromised system integrity.
To stay ahead, designers, original equipment manufacturers (OEMs), and system integrators must evolve HV protection strategies to align with cutting-edge trends. This article explores how HV components contribute to the success of EVs, what materials are best suited for the job, and how innovation ensures these critical systems can meet the demands of modern mobility.
The role of HV systems in next-gen vehicles
HV components are the backbone of modern EV platforms, supporting vital systems like traction batteries, electric motors, and onboard charging units. These systems help power architectures evolve from the current 400 volts to 600 or even 800 volts, unlocking the potential for ultra-fast charging. For instance, an 800-volt charging system can achieve a five-to-80% charge in under 23 minutes, compared to 40-120 minutes for a traditional 400-volt setup.
The importance of this advancement cannot be overstated. By significantly reducing charging times, drivers are better equipped for long trips with less ‘range anxiety’, a key barrier to EV adoption. Countries leading in EV innovation, such as China, have already achieved breakthroughs in charging times as low as five minutes, setting a global benchmark.
However, with higher voltages come new risks. HV systems produce various energy types, including electrical, thermal, and chemical, which can degrade components and pose safety hazards. Without proper insulation or shielding, the consequences can include thermal degradation, mechanical fatigue, short circuits, and thermal runaway.
Heat shrink tubing: a reliable solution for HV insulation
Why insulation matters
Heat shrink tubing plays an essential role in insulating HV connectors, wiring harnesses, and interlocks. Its characteristic bright orange colour instantly signals its purpose in high-voltage applications, ensuring technician and end-user safety. Unlike traditional taping or moulded components, heat shrink tubing offers consistent performance and scalable manufacturing processes, avoiding the bulk of taped overlays and the rigidity of moulded parts.
There are a range of formulations that are blends of polymers and additives that are carefully designed to meet stringent customer demands and internal specification requirements. They meet international standards and OEM approvals in many electronics markets. The selection of polymers, flame-retardants, antioxidants, UV-stabilisers, and other additives is of great importance for products to meet requirements of properties such as tensile strength, elongation at break, flame retardancy, continuous operating temperature, heat shock, heat ageing, flexibility, chemical and solvent resistance, and, shrink temperature.
Other formulations include hot melt adhesives that are specifically formulated to be compatible with individual heat-shrink tubing compounds. These adhesives include a balance of polymers and additives that allow the adhesive to melt, flow, seal, and adhere to a range of substrates at the shrink temperature of the overall tubing.
Technology innovations in heat shrink tubing
Heat shrink tubing can be used for a wide range of applications across many industries and environments because it is reliable, robust, and easy to use. One of the reasons for this is cross-linking technology. Radiation cross-linking enhances the polymer properties and provides heat-shrinkability or shape memory. Polymeric tubing is extruded and in a separate process the chemical structure is modified to provide improved properties such as reduced deformation under load (creep), improved chemical and solvent resistance, increased abrasion resistance, improved impact properties, and shape memory characteristics. Due to the three-dimensional cross-links which are formed during the cross-linking process, the tubing does not melt and obtains its perfect shape memory.
Single-wall vs. dual-wall tubing
Heat shrink tubing comes in two primary
configurations to meet varying needs:
- Single-wall tubing: provides basic protection, including strain relief and mechanical damage resistance, while offering flame retardance
- Dual-wall tubing: features engineered adhesives liner for enhanced moisture and dust protection, combining environmental sealing with mechanical and electrical insulation
For modular EV platforms using busbars instead of wiring harnesses, lightweight tubing allows for compact insulation without compromising durability.
This innovation supports the trend toward modular battery packs, where space, connectivity, and thermal management play crucial roles. For example, TE Connectivity’s VOLINSU polyolefin heat-shrink tubing represents innovation tailored for next-gen EVs and E/E architectures as its designed specifically for high-voltage applications up to 2,500 volts and provides superior electrical insulation and durability.
EMI shielding for next-gen EVs and E/E architectures
Growing risks of EMI
The rising complexity of E/E vehicle architectures has increased Electromagnetic Interference (EMI) risks. Advanced systems like driver assistance technologies (ADAS), infotainment platforms, and wireless communication hubs generate high and low-frequency interference, which can compromise the performance of interconnected
systems. For example, electromagnetic crosstalk between a battery management system and a navigation unit could disrupt critical operational data, posing safety concerns. Shielding helps prevent Electromagnetic Interference (EMI), which accelerates as voltages and interconnects increase.
Shielding strategies across system levels
To mitigate EMI, effective shielding must be implemented at multiple levels:
- Enclosure level: EMI shielding of enclosures effectively involves a Faraday cage to attenuate signals from within the enclosure. This minimises signals escaping and causing interference to other equipment within the environment and can prevent outside interference from penetrating the enclosure
- Module level: module-level shielding is the shielding of active components, such as drives, displays, etc., within the electronics enclosure to protect those components from internal interference
- PCB level: shielding at the PCB level consists of shielding of individual components, such as integrated circuits, with shielding cans, for example, making a small Faraday cage for those components
Materials for EMI shielding
Advanced materials are critical in combating EMI effectively. Examples include:
- Conductive elastomers: silicone or fluorosilicone bases embedded with conductive particles, offering both shielding and environmental resistance
- Oriented wire gaskets: feature fine metallic wire embedded in a silicone matrix, ensuring precision conductivity
- Knitted wire mesh gaskets: durable solutions for harsh environments, often made from nickel-copper alloys or stainless steel
Pushing boundaries with sustainable solutions
Sustainability is a growing focus in the automotive industry, and material science is leading the charge. TE Connectivity’s BIOFUSE bio-based shrink tubing is a prime example of how renewable materials can replace conventional options without sacrificing performance. By choosing solutions like these, manufacturers not only
improve their environmental footprint but also align with global sustainability goals.
Emerging trends in HV component protection
Several trends are shaping next-gen EV designs:
- Modular battery packs: encouraging the shift from traditional wire harnesses to busbars for greater current-carrying capacity and improved thermal management
- Electrification and autonomy: demanding more robust EMI protection for interconnected systems within autonomous vehicle platforms
- Automated processes: increasing adoption of automated wire harness assembly enhances productivity and reduces costs
- Global regulatory focus: stringent regulations on safety and sustainability are shaping material innovation
Collaborating for safer, smarter vehicles
The successful evolution of EVs depends on ongoing collaboration between designers, OEMs, and material scientists. By working together, these stakeholders are driving innovations that enhance safety, sustainability, and performance. Leveraging advanced solutions like heat shrink tubing and EMI shielding, the industry is equipped to meet the challenges of next-gen EV and E/E architectures. Together, the vision of sustainable transportation can become a reality, revolutionising mobility for generations to come.
This article originally appeared in the June’25 magazine issue of Electronic Specifier Design – see ES’s Magazine Archives for more featured publications.
