Electric cars, both fully electric and hybrid vehicles, increasing in popularity means larger differences in materials, joining requirements, and processes of manufacture. Significant numbers are now being manufactured, as environmental issues increase the demand for electric/hybrid electric vehicles (EVs). TWI is at the forefront of innovations in electric powered vehicles and can offer help with the processes involved in this industry.
Exhaust pipe emissions of carbon dioxide (CO2) from motor vehicles contribute a significant proportion of the greenhouse gases responsible for global warming. Road transport emits about 25% of Britain's total CO2, with passenger cars alone accounting for nearly half that figure, and car use is continually growing all over the world. Britain alone now has a fleet of 27 million cars.
It is recognised globally that the internal combustion engine is a very big part of the climate change problem, and that transport will have to be "decarbonised," limiting the use of fossil fuels as part of the worldwide move to cut greenhouse gas emissions and increase energy efficiency.
International competition for EVs is intensifying as new manufacturing facilities are being opened in China, USA, Malaysia, and Europe.
The batteries in a battery electric vehicle (BEV) must be recharged periodically. BEVs most commonly charge from the national power grid, through a domestic plug charging point, public charging stations, or a bespoke commercial outlet.
Although charging time is limited by the capacity of the grid connection, BEVs are normally designed to be fully charged overnight. The charging infrastructure required to support electric/plug in hybrid vehicles itself has many technical issues, which require the development of low-cost, reliable mobility solutions. TWI can assist companies in this area.
For more information, please email:
EV at TWI
Battery Modules and Packs
TWI offers extensive support in the manufacturing of the entire module and battery pack. This includes a wide range of the engineering and welding processes required for electric cars, such as:
- Developing preliminary (pre-qualified) Laser Beam Welding Procedure Specifications (WPSs), in line with electrical and structural joint requirements within the battery modules and packs
- Joining lattices and busbars to the terminals of prismatic, pouch and cylindrical cell designs, joints involving different dissimilar material combinations (aluminium, copper and steel, typically) for coated or uncoated materials, and for a variety of different material grades and thicknesses
- The manufacturing of structural welds in the joint configurations used in battery casings, with welding experience of aluminium alloys and steels in different thicknesses able to be customised to specific applications
- Tailored tooling for laser welding is a critical task for successful laser welding and successful scale-up of the technology (e.g. from cell to module to pack level), with engineering specialist support provided for the design and manufacture of tailored welding tooling
In-line Process Inspection Validation (During Welding)
TWI is also involved in sensor technologies through industry-driven, real-time dynamic control of laser welding. In this area, TWI can support the following fields of research:
- Application-specific multi-sensor solutions
- Bespoke signal analyses
- Predictive controls
- Assessments of the capabilities of selected sensor technology, robustness, repeatability and limitations of the selected inspection method
Cell Handling and Module Assembly/Testing Facility
TWI can advise on infrastructure and safety procedures for battery prototype production. Onsite capability includes:
- A dedicated laser welding facility for joining live EV modules (e.g. cell terminal to busbar joints), along with the necessary (Risk Assessment Method Statements) RAMS documentation and fully-qualified trained operators in High Voltage (HV) testing
- A dedicated cell handling and module assembly/testing facility (in temperature/humidity controlled environment), along with the necessary RAMS documentation
- A dedicated storage site for the cells and welded modules, along with the necessary RAMS documentation
- Assistance with arranging packaging and delivery of battery modules in normalised UN protective casings
State-of-the-art Laser Capability:
- Latest generation single mode lasers for improved coupling in high conductive material (Aluminium – Copper – Stainless Steel)
- Latest generation multi-mode/multi-kW lasers for structural welds
- Versatile wobbling heads and scanners for tailored energy distributions, with variety of beam oscillation modes and patterns
Beginning of Operational Life (BoL) and End of Operational Life (EoL) Testing:
- Cell inspection: Dimensions and shape, open circuit voltage OCV testing
- High voltage testing: Insulation testing between cells and between cells and case structure