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How Simulation Provokes Better EV Battery Designs

Oct. 20, 2020
Electric-vehicle manufacturers are leveraging simulation to not only improve battery design, but also to scale production and continue meeting industry demands for sustainable transportation solutions.

What you’ll learn:

  • How simulation and a collaborative platform approach enables EV manufacturers to improve battery design, scale production
  • Potential roadblocks and solutions

There are many good reasons for electric-vehicle (EV) use, chief among them sustainability. As proof, a 2018 paper from J.P. Morgan on global energy trends states that road transportation (i.e., internal combustion engines, or ICE) accounts for 50% of worldwide oil consumption.

The best way to reduce this figure, the paper suggests, is widespread adoption of electric vehicles. Together with renewable energy sources such as wind and solar, EVs will set the human race on a greener, more planet-friendly path.

However, the battery pack is the largest, most expensive component in an EV. Designers must therefore find novel ways to reduce both cost and size, squeezing batteries into EVs without sacrificing passenger comfort or cargo space, while also making them fit into the owner’s budget. Achieving these goals will require advanced engineering tools that are able to predict, simulate, and optimize battery behavior even down to the molecular level.

EV Sales and Their Connection to Falling Battery Prices

Over the past five years or so, EV sales have grown dramatically. The International Energy Agency notes that, from a mere 230,000 battery-powered and hybrid cars in 2013, nearly 15 times that many (3.29 million) were on the road just five years later. And not long before the global pandemic struck, accounting firm Deloitte was predicting that world EV production would top 4 million cars this year, with annual sales reaching 12 million by 2025 and 21 million in 2030.  

Much of this growth is due to falling battery prices, the Deloitte study states, with the year 2022 slated as the “tipping point” where the cost of owning of an EV will be comparable to that of a conventional ICE-powered vehicle. Bloomberg NEF’s most recent Battery Market Survey supports this trend, reporting the price per kilowatt-hour for lithium-ion batteries has fallen from $1100/kWh a decade ago to just $156/kWh in 2019 (an 87% reduction), and is expected to average $100/kWh by 2023. Most industry experts consider this to be the point at which EVs will become cost-competitive with vehicles using gas or diesel fuel.

Potential Roadblocks to Advancing EVs

Although these costs have dropped significantly over the years, that trend may be slowing given battery manufacturers’ dependence on rare earth metals such as dysprosium, neodymium, and terbium—all rare earth metals are seeing increased demand and commensurately rising prices. 

On top of this potential roadblock is infrastructure. EVs require electricity to charge their batteries, after all, and supplying power to a global fleet of them will mean more charging stations, more power generation facilities, and more transmission lines—not to mention the factories required to build these batteries. Simulation software and other advanced engineering tools will be needed to help streamline the design and construction of these critical components.

This will require both a commitment from governments everywhere to build additional infrastructure and significant efforts by battery engineers and vehicle designers alike. And, in some cases, it will require significant technological leaps. Battery manufacturers must not only reach the kilowatt-hour target just mentioned, but also make their wares safe, long-lasting, fast-charging, and with sufficient range so that drivers don’t have to worry about the distance to their destination.

Lithium-Ion Battery Performance in EVs

Lithium-ion batteries are pervasive in today’s world, powering smartphones and laptop computers. Those found in EVs use the same technology. But if a computer battery dies, one can simply plug it in and wait for it to recharge. This, of course, isn’t the case when relying on an EV for necessary transportation.

In addition, the batteries used in smartphones and laptops don’t cost tens of thousands of dollars and are generally traded in when the next-generation device comes along. Electric vehicles, on the other hand, are expected to last a decade or more, and provide the same range and load-carrying capacity at the end of that service period as they did when leaving the showroom floor.

Of course, much of a lithium-ion battery’s performance depends on its care, usage, and operating environment. For instance, consumers should not make a habit of fully charging their electric cars to 100%. Nor should they run them down to zero, lest the voltage drop so far that the battery becomes damaged or "bricked,” a term that Tesla made popular (or unpopular, actually) after a customer left his Roadster unplugged for more than two months and ended up with a $40,000 repair bill.

Extreme temperatures may also have a negative effect on battery performance. Tesla mitigated this by adding liquid-cooling systems to some of its models, although this undoubtedly adds to vehicle cost.

Even a properly charged and cared-for battery tends to deteriorate over time. However, this unfortunate fact is offset somewhat by the fact that the batteries in most EVs have more power than the car’s powertrain can handle, thus making the gradual loss of power unnoticeable by most consumers. What they will notice, though, is the loss of range and the more frequent charging needed to keep up with daily demands.

Thus, two possible scenarios emerge. In the first, battery designers will continue to optimize existing lithium-ion technology to achieve the “tipping point” described earlier. In the second, they might develop an entirely new technology that leverages potentially new electrochemical processes—a breakthrough like the internal combustion engine and Ford’s assembly line were to a generation of horse-and-carriage drivers more than one century ago.

Researchers at one of the nation’s most prestigious institutions concur. A new report from the MIT Energy Initiative warns that as long EVs rely on lithium-ion batteries, their sticker prices may never reach those of ICE vehicles, even though the total cost of ownership will likely reach parity within the next 10 years or so. The paper went on to state, “Battery price projections beyond 2030 are highly uncertain and are likely to be disrupted by the development and commercialization of new battery chemistries.”

The Collaborative Effort of Building an EV Battery

Whether EVs roll forward with new battery technologies or further optimize the old, those who design them will need powerful engineering tools if they’re to meet industry targets while simultaneously achieving internal cost and efficiency goals. Despite their simplistic appearance, batteries are highly complex systems, requiring teams of knowledgeable people collaborating on their development:

  • Battery-cell material designers, for example, must understand cell behavior at the nanoscale level. They need to predict how electrolytes will interact with anodes and cathodes, simulate current flow and molecular oxidation, and visualize what role each element plays in the electrochemical dance within.
  • Battery-cell engineers take these microscopic interactions to the macro scale. They use multi-discipline simulations to optimize individual battery cells for maximum energy, lifespan, and safety. They watch what happens when cells are virtually punctured or smashed, and learn how to make cells safe in the event of a crash.
  • The battery module and pack engineer go one level higher, ensuring structural integrity and optimal thermal management of each module and the packs within, while the battery-management system designer simulates overall battery behavior, as well as its interaction with auxiliary systems.
  • Lastly, the battery system engineering and vehicle integrator is responsible for battery integration with the rest of the vehicle, and assure battery performance optimization under a seemingly infinite variety of driving scenarios and environmental conditions.

Each of these team members requires engineering software able to perform these functions and more. And for the industry to achieve reliable, innovative battery improvements, a collaborative business platform is needed to unite all of these functions. 

On that front, Dassault Systèmes’ 3DEXPERIENCE is a solution garnering more attention. Its platform enables companies to create accurate engineering simulations starting right at the molecular level. Then the product design and engineering team can perform cradle-to-grave analyses of the battery system, predicting how each level will fare under different conditions while giving engineers the insights needed to optimize battery performance.

In addition, realistic simulations of real-world possibilities such as overheating, thermal runaway, punctures, and extreme weather help ensure battery viability. This allows engineers to safeguard batteries against these eventualities, all in a virtual environment.

Yet the need for accurate simulations extends to other EV components, and even to the vehicle as a whole. Simulations are so predictive that their feedback can replace expensive and time-consuming track and laboratory testing while providing greater insight into the physics of vehicle design. These include, for example, analyzing airflow to reduce vehicle drag, or simulating antennae placement for vehicle-to-vehicle (V2V) communications. Designers can check for EMI and thermal buildup across all of the vehicle’s systems and gain a deeper understanding of road noise, vibration, dirt buildup, and other factors that might impact electric-vehicle performance.

Perhaps the most important pieces of this equation are interoperability and collaboration. Each of the disparate teams just listed must work together in an effective manner. They must eliminate duplicate efforts and provide complete visibility to one another’s work. They should also be able to share their vision with the marketing people, the finance department, the production floor, and any others with the organization who will be impacted by their decisions, or possibly have their own suggestions.

Only through the use of a comprehensive design and simulation software platform—one that brings together all of a company’s engineering disciplines—is it possible to achieve strategic insights and overall business performance.

Real-World Successes

One company that knows about the challenges of EV manufacturing is Austria-based Kreisel Electric. Using the 3DEXPERIENCE Electro-Mobility Accelerator solution, engineers converted a gas-powered 1971 EVEX Porsche 910 into “an electrified supercar.” Doing so required that the team design and build a custom battery pack, cooling system, gearbox, and powertrain to fit the car’s tight quarters, all of which called for a high degree of collaboration to keep the budget in check and project timeline on schedule.

Founder Philipp Kreisel said 3DEXPERIENCE helped “reduce the car’s development cycle by 50%, leaving more time for innovation,” while head of mechanical engineering Helmut Kastler noted that positioning of the gearbox and battery pack in the car’s limited space “could not have been done in time and with this quality without this platform.”

Battery expert Kim Yeow shares a similar story. A technical specialist at AVL North America Inc., Plymouth, Mich., he and others at AVL were challenged to design a cooling system for a Li-ion battery pack comprised of 14 off-the-shelf modules. As with the Kreisel Electric example, quarters were tight and expectations were high. Yeow used the Abaqus FEA (finite element analysis) software from Dassault Systèmes to simulate, predict, and validate the pack’s thermal and electrical performance.

“There’s still a lot to learn about batteries, and due to a large market shift, there’s been heavy research on vehicle electrification for the past few years within AVL,” said Yeow. “From a performance and safety standpoint, we would like to maintain an optimal operating temperature range for the battery pack regardless of the ambient temperatures and operating conditions. Abaqus was a good fit for analyzing this and has therefore become our tool of choice for structural evaluation of the electrical and thermal behavior of lithium-ion batteries.”

The Future Impact of EVs

EV acceptance goes beyond just robust batteries, though. There are power-generation grids to design; durable, low-cost, and easy-to-deploy charging equipment to build; and highly efficient, quite possibly automated factories to crank out batteries at unprecedented production volumes. Here again, highly effective design and simulation tools pave the way forward.

By employing intelligent digital models of the production floor, engineers can make better decisions earlier in the design process, reducing costs. Similarly, large-scale deployments of charging stations and other electrical infrastructure become more predictable and less risky.

Engineering software aside, it’s an exciting time for all involved. If the EV industry is successful, future generations can look forward to cleaner skies. There will be fewer conflicts over what’s buried beneath a patch of ground, fewer environmental disasters, and fewer concerns over global warming.

As for the driving public, it stands at the cusp of a profound change in how we get around. The days of waiting in line at the gas station will become an anachronism. Oil changes will give way to software updates, and exhaust systems will give way to silence. We might miss the rumble, but it's tough to argue with clean, quiet, and sustainable.

Ed Tate is Industry Process Senior Director, SIMULIA, at Dassault Systèmes.

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