Auto manufacturers are shifting larger proportions of their fleets to zero-emission vehicles and electric vehicle (EV) salesare projected to grow from 3.4% of new-car sales in 2021 to approximately 29.5% by 2030.
Despite electrification targets of governments and tax incentives offered consumers, EV and fuel-cell cars are not being adopted quickly. Consumers hesitate because of the price and concerns about engine power and battery range, particularly because the charging infrastructure in the US is rudimentary. Auto manufacturers have increased battery range up to 250 or even 300 miles in some vehicles but range anxiety continues to be a major barrier.
Major improvements to energy optimization and battery mass will bring vehicle price down and driving range up. Automakers are establishing larger, secure pipelines for battery supplies like lithium, cathode materials, and electrolytes. Established battery-cell suppliers and startups are rushing to improve battery design and production capabilities. According to Automotive Logistics, more than 100 massive battery-manufacturing plants are being built or expanded around the world, some by major auto manufacturers, others independent. Yet experts are predicting the lag in battery production will slow the growth of the EV market.
Additive manufacturing (AM) has potential to accelerate energy optimization in EVs, helping reduce range anxiety in drivers, speed up innovation in the EV industry, and ease the supply chain constraints afflicting battery manufacturers.
Improvements in additive manufacturing materials and equipment
AM was primarily used for designing prototypes, as the polymer-resin parts produced may have been too brittle or degraded significantly with use. However, this technology sector has made strides in developing new polymers and metals, new production capabilities, and enhanced integration with design with far-reaching implications for EV and fuel-cell manufacturers.
Using AM to improve battery efficiency and range
Automakers are leveraging AM to solve complex design and lightweighting challenges throughout the body of the car. As they redesign powertrain systems to accommodate electric batteries or solid-state fuel cells, redistributing the motor, finding space for large battery packs, and making hard-point shifts in different zones in the vehicle are needed. Manufacturers are using 3D printing to consolidate components throughout the chassis and reduce the parts' overall weight by as much as 30% to 40%, improving battery range in the process.
Manufacturers also use AM to fabricate parts with more complex shapes. This can reduce the inertia of rotating components, improve the efficiency of cooling systems and fluid exchange, and optimize systems for improved thermal performance to extend the range of the vehicle in the short term and lengthen the life of the battery in the long term.
AM allows manufacturers to refine the package for batteries and fuel cells, increasing the density of the power system. They can fabricate casing with more intricate shapes and thinner walls than die-casting or molding permits, allowing the manufacturer to stack battery plates more efficiently within the propulsion system.
The high-current, high-heat power systems found in electric vehicles have completely different failure modes than the 12-volt batteries used in internal-combustion engines. With higher voltage and higher currents flowing through the vehicle comes the increased severity of shorting failures and even the possibility for interference affecting individual systems. It’s critical to keep high-current, high-cycling cables separate from signal cables for electromagnetic compatibility. AM can produce complex routing channels to contain the flow of electricity within individual systems and reduce failure mode occurrences. It helps engineers design more flexible cooling components for each system to lower the heat stress.
Battery makers are turning to AM to redesign the structure of the fuel cells themselves. Working with smaller-scale lithium-ion batteries, researchers from Carnegie Mellon have produced electrodes with micro lattice structures that increase energy density and discharge rates, processes that are being brought to scale by companies in Switzerland and the United States.
Scaling up AM and using AM to scale up
There are two key factors to integrating 3D-printed components in production of electric vehicles and batteries. The first is bringing this technology into facilities. As the AM sector evolves, print-time efficiency and speed are growing, and more AM systems are being used in factory line production, interfacing with automated guided vehicles, and supporting manufacturing.
The second is the introduction of new materials. The quality of parts produced through metal powder-bed fusion is rising and achieving gains in productivity. The use of AM technology with high-end materials such as titanium is widespread, but automakers look for more economical, general-use materials such as aluminum alloys and copper. AM systems can use high-strength, high-performance aluminum alloys such as Scalmalloy, certified for use in Formula One cars and now making their way into the commercial auto manufacturing sector. New resins are reaching the market suited for long-term use are allowing for functional parts with out-of-printer surfaces that rival injection molded components. Parts can be made with the intricate features required for EV innovations while meeting critical mechanical and thermal properties over the life of the vehicle.
As the race to convert manufacturers' automotive fleets to EV speeds up, the need for rapid innovation grows ever more acute. AM continues to play a critical role in prototyping and advancement of batteries, fuel cells, and assemblies, allowing engineers to move from idea, to design, to testing, and to re-iterating new components without long lead times.
New software allows designers to marry digital analysis to AM systems to twin digital and physical components for testing purposes. Engineers use AM to produce an exact physical representation of a new part or system, then test both the physical model and the digital model at the same time, closing the loop on iterations. Digital twinning allows development teams to accelerate innovation through digital means while providing the confidence and risk mitigation of physical verification. The number of iterations is typically limited with traditional prototyping lead times, but AM coupled with functional materials that reflect production properties allows more iterations that are digitally and physically verified.
Manufacturing supply chains have suffered frequent unexpected gaps and delays. These interruptions are shifting to address supply chain concerns through AM, whose systems can ramp up production of EV batteries and fuel cells and be used as a hedge to step in when the supply chain becomes temporarily blocked.
The transition to EVs is sparking innovation in every aspect of how automobiles are designed and fabricated. Integrating advances in AM systems and materials speed up product development in electric batteries and fuel cells, relieve heat pressure, reduce component mass, and extend battery range, all while protecting the supply chain against interruptions.