Evolution of EV platforms: Innovations in design, manufacturing, and scalability

Adaptable to different vehicle types, simple to standardise, scale and assemble, lightweight and cheap to produce. These are the criteria for electric vehicle (EV) architectures to meet, but as we see variable demand and new technologies are driving rapid design, development and manufacturing changes in these vital structures.

EVs are not new; there have been versions around since the 19^th century and since then this vehicle segment has seen much ebb and flow in its development, but over recent years there has been an intense focus on designing, developing and manufacturing an entirely new generation of EV platforms as the automotive industry attempts to make the huge step of transitioning to an electric powertrain future.

Toyota took an early lead in this area with high volume production of its Prius hybrid model starting in 1997. Hybrids in various guises were seen as a market step stone to the eventual introduction of full battery electric vehicles (BEVs) and although the Prius has seen healthy sales, hybrids have mostly been built on modified ICE platforms, with the higher parts content and complexity increasing production costs.

For their pure electric BEVs, OEMs have looked to develop dedicated vehicle platforms that suit the above-mentioned criteria, and among the most popular design has been the ‘skateboard’ configuration featuring the battery pack in the floor and the motors, steering, braking and suspension systems mounted to subframes at each end. This is a relatively simple design, which allows for easy changes in wheelbase and body style depending on the vehicle segment. It can also accommodate the different battery formats (cylindrical, prismatic and pouch) that are currently in use for automotive applications.

Most high-volume producers, such as Tesla and VW have adopted this approach, but these seemingly simple designs disguise the greater complexity involved in reinventing the vehicle architecture. Battery integration into the vehicle body can be challenging in a high-volume production process, as is the need for the packaging of the electronic control systems in the available space and perhaps most important the thermal management of the battery cells.

Added to this, these dedicated EV platforms present challenges in meeting crash protection requirements for both passengers and batteries. With less front and rear structures required with the removal of ICE powertrain and fuel system, crash protection has had to be redesigned. Side impact is also a big factor in protecting the battery and the once humble rocker panels are now highly engineered, multi-layered components, designed to absorb high impact forces with now comprise to the battery pack.

Along with new developments in battery chemistries and packaging, the introduction of new production processes, such as gigacasting and gigastamping are supporting the continued evolution of EV platforms. More recently shifting consumer demand is also a big driver in the architecture design, with a renewed focus on hybrids and even newly developed platforms that will now accommodate BEV and ICE configurations.

This continued development journey to find the optimum EV platform design is not only driving innovation in manufacturing technologies and materials but also making car makers and tier suppliers to rethink their respective approaches to the entire vehicle development process. As competition intensifies, speed to market for new products is vital and design, engineering and manufacturing ramp-up timescales are becoming much shorter, and no one can afford to be left behind.