The enclosure made from CFRP is 40% lighter and brings several other benefits

SGL Carbon, the company that several years ago worked with BMW to introduce i3/i8 mostly-CFRP cars, is currently engaged in making carbon-fiber battery enclosures with various OEMs.

According to SGL, demand for lightweight battery enclosures will grow rapidly in the next few years as manufacturers are doing whatever possible to make electric cars lighter.

The carbon-fiber-reinforced plastic (CFRP) has a reported potential to be 40% lighter than comparable solutions, mainly made of aluminum and steel.

One of the first projects is the fully integrated composite battery enclosure for NIO, shown recently at the 2019 Shanghai Auto Show.

"In collaboration with SGL Carbon, Chinese automotive manufacturer NIO has developed prototypes for battery enclosures made of carbon-fiber reinforced plastic (CFRP) for its NIO high performance electric vehicles. Thanks to CFRP, the battery enclosure is extremely lightweight, stable and safe. The entire battery enclosure, including the batteries, can be changed at swapping stations of NIO within just three minutes."

SGL Carbon lists several advantages of CFRP:

  • around 40% lighter
  • enclosures’ stiffness
  • the approximately 200 times lower thermal conductivity of CFRP compared to aluminum (better shields the battery from heat and cold)
  • excellent values in terms of water and gas leakage tightness and corrosion resistance

NIO adds that thanks to CFRP, the pack energy density could be above 180 Wh/kg, and improves dynamic performance and range.

"These outstanding battery enclosure characteristics mainly owe to the bottom and cover plate design, combining a sandwich core with multiple layers of carbon fiber non-crimped fabrics. SGL’s own Lightweight and Application Center was responsible for developing the tool to produce the bottom and cover plate. Along the fully integrated value chain, carbon fiber is produced for these components at the SGL plants in Moses Lake and Muir of Ord, processed into non-crimped fabrics in Wackersdorf. Besides producing the bottom and cover plate, the SGL site in Ried, Austria, also assembled the individual components."

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SGL Carbon produces prototypes of fully integrated composite battery enclosures for NIO’s Advanced Technology

04/30/2019, Wiesbaden

At a glance:

  • Fiber-reinforced battery enclosure 40 percent lighter than comparable aluminum solutions
  • Increased driving dynamics and safety
  • Further projects with various OEMs

In collaboration with SGL Carbon, Chinese automotive manufacturer NIO has developed prototypes for battery enclosures made of carbon-fiber reinforced plastic (CFRP) for its NIO high performance electric vehicles. Thanks to CFRP, the battery enclosure is extremely lightweight, stable and safe. The entire battery enclosure, including the batteries, can be changed at swapping stations of NIO within just three minutes. NIO presented the swap concept at NIO Day in December 2017 for the first time and now demonstrated the actual system along with various technological innovations including the CFRP battery enclosure live at the 2019 Shanghai Auto Show last week.

“Commercial battery enclosures for electric vehicles are mainly made of aluminum and steel. In comparison, the CFRP battery enclosure is around 40 percent lighter. Other benefits include the enclosures’ stiffness and the approximately 200 times lower thermal conductivity of CFRP compared to aluminum, which better shields the battery from heat and cold. Plus, the composite also offers excellent values in terms of water and gas leakage tightness and corrosion resistance,” states Sebastian Grasser, head of market segment Automotive in the Composites – Fibers & Materials business unit at SGL Carbon.

“Lightweight technology is one of the core elements in NIO technology roadmap. Using composite material especially the high-performance carbon fiber in battery enclosure system, our vehicle can achieve better dynamic performance, increase range, and obtain remarkably high energy density of the battery pack (over 180 Wh/kg). These features fit perfectly to the core values of NIO brands of ultimate product and system efficiency” states Bin Wei, Senior Manager of Lightweight Engineering at NIO.

These outstanding battery enclosure characteristics mainly owe to the bottom and cover plate design, combining a sandwich core with multiple layers of carbon fiber non-crimped fabrics. SGL’s own Lightweight and Application Center was responsible for developing the tool to produce the bottom and cover plate. Along the fully integrated value chain, carbon fiber is produced for these components at the SGL plants in Moses Lake and Muir of Ord, processed into non-crimped fabrics in Wackersdorf. Besides producing the bottom and cover plate, the SGL site in Ried, Austria, also assembled the individual components.

SGL Carbon expects demand for lightweight solutions for battery enclosures in the automotive sector to grow rapidly in the next few years due to increasing electromobility. The company is already working with various partners to continue developing different battery enclosures made of composites with the aim of scaling them for electric vehicle batteries of all sizes and designs.