IndustryNEWS Electric vehicles on the rise China is leading in electric vehicles adoption, against the back of reducing CO2 emissions, oil concerns, growing congestion and automotive advances. In fact, the Chinese government has extended its large pilot programme to 25 cities, says a new report by consulting firm PRTM and the World Bank. Even though China’s plan is to invest US$15 billion into this industry, other countries are now moving quickly to realise the opportunities of e-mobility. The study estimates that global sales will likely comprise 10% of new vehicle sales by 2020. This rapid growth is expected to usher in a new global electric vehicle (EV) era estimated to be worth US$250 billion worldwide in ten years. Yet, the countries face steep challenges including vehicle-charging infrastructure, need for common standards, safe equipment, new business models for batteries, consumer acceptance and grid storage.
Meanwhile in Germany, Sabic is collaborating with powertrain specialist IAV to develop materials that can replace metal and optimise lightweighting in EVs and hybrid powertrains. To sustain the full environmental advantages of hybrid, plugin hybrid and battery EVs, the additional weight of battery packs – up to 300 kg on a mid-sized car – needs to be offset by weight reduction in other areas. This is where PPO and PBT resins from Sabic can replace steel in battery frames and housings. The increasing use of lithium ion and lithium polymer batteries, which have higher power and energy density, requires thermal management solutions. To control temperature, liquid cooling often replaces air cooling and if power is withdrawn from a battery, it will heat up. As a result, these liquids require chemical and temperature resistant materials like Sabic’s PEI and PBT resins.
Lanxess’s PAs and PBTs are in demand in the manufacture of plug connectors for EVs
In hybrid-electric vehicles, the higher the voltage, the more important electromagnetic interference/radio frequency interference (EMI/RFI) shielding becomes to control the potential disturbance from the different electronic components such as inverters, electronic control units and battery management system. LNP Faradex compounds from Sabic cater to this. Meanwhile, EVs rely on battery power for heating and air-conditioning, making insulation more vital to avoid a heavy drain on the battery. Sabic’s Lexan PC glazing is said to offer five times the insulation performance of glass while specialised infrared (IR) absorbing grades of Lexan can further optimise airconditioning by reducing the amount of heat load transferred to a vehicle’s interior in hot climates or sunny weather. Another German company Lanxess also supplies its PA and PBT for batteries and electrical/ electronic components in EVs. For battery trays that need to be lightweight while also exhibiting a high absorption capacity for crash energy, Lanxess has a plastic-metal composite or hybrid technology based
The Sabic/IAV collaboration will explore material solutions for powertrains
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on PA6 and sheet steel or aluminium. It allows for 30% lower weight compared to similar sheet steel solutions. PA and PBT can also be used in place of other materials for non-loadbearing battery components, such as battery covers and power electronic housings. Components like these mostly need to offer protection against electromagnetic radiation and have been made of metals or sheet moulding compounds (SMC) that are metallised/coated with an electrically conductive coating. An alternative is to use highly reinforced, stiff PA and PBT grades that can be vaporised with aluminium after the injection moulding process. The metallising step can be eliminated if the manufacturer uses electrically conductive PA6, 66 or carbon fibre-filled blends, which Lanxess says it is already at an advanced stage of development. Due to the high voltages and strong currents present in the area of the batteries and drives of EVs, it can be assumed that flameretardant material grades will be required here like Lanxess’s Durethan AKV 30 FN00 PA66 that offers high tracking and is free of red phosphorus and halogens.
Plastics and Rubber Asia May 2011 Electronic Issue