GM Develops Lower Cost Ultium Lithium-Ion Batteries To Power New Electric Vehicle Line
General Motors new Ultium battery system for its upcoming lineup of electric vehicles STEVE FECHT FOR GENERAL MOTORS
It’s been just over 29 months since General Motors announced that it would launch 20 zero-emission vehicles by 2023. Since that time exactly zero of those vehicles have actually arrived at dealerships. In fact, we’ve lost two of the plug-in vehicles that GM was selling at the time, the Chevrolet Volt and Cadillac CT6 plug-in hybrid. While GM has continued to emphasize its intention to go electric, details have been few and far between. That changed on Wednesday with an event at the GM Technical Center in Warren, Michigan.
The company official revealed details of its new BEV3 electric-propulsion system. As implied by the name, BEV3 represents the third major generation of GM’s dedicated electric propulsion technology. BEV2 is the current Chevrolet Bolt while BEV1 goes all the way back to the legendary EV1 of the 1990s. What BEV3 is not, is a specific vehicle platform.
At the core of BEV3 is what GM is calling its Ultium battery system. This is based on a newly developed chemistry for the lithium-ion cells that helps reduce the cost and improve the performance of the battery. Most current EVs utilize what’s known as an NMC chemistry comprised of nickel, manganese and cobalt coatings on the cathodes.
Most automakers and cell manufacturers are working to reduce or eliminate cobalt because of the cost and the conditions where it’s mined, primarily in central Africa. GM’s Ultium cells use an NMCA chemistry with the A being aluminum. This has allowed the cobalt content to be reduced by 70%.
The chemistry will be proprietary to GM products but was developed in collaboration with LG Chem. GM and LG are continuing to develop new chemistries with the eventual goal of eliminating both cobalt and nickel entirely. We were also shown a lithium metal test cell that should eventually double the energy density.
General Motors Ultium electric drive systems STEVE FECHT FOR GENERAL MOTORS
The new cells will be produced at the new GM-LG Chem joint-venture plant in Lordstown, Ohio. Until that plant is fully operational in late-2022 or 2023 other LG Chem facilities will provide the cells. GM has is open to eventually licensing these cells to other companies for uses such as stationary storage.
GM is claiming that the new chemistry will drive cell cost down below $100/kWh. During the presentation, Doug Parks, executive vice-president for global product development, said the cell cost now represents 80% to 90% of the total cost of the battery. In the past, the rule of thumb has been that large-format cells represented about 60% to 65% of the total pack cost with the rest being the casing, wiring and other components. For small format cells like those used by Tesla, the proportion was reversed because of the higher part count.
GM has accomplished a substantial reduction in the complexity of the pack for Ultium through increased integration. The battery management system is now integrated into the modules rather being a separate component. This helps slash the wiring by about 80%. More importantly when a module is assembled the BMS is programmed with information about the chemistry of the cells inside. This allows the BMS to manage the output of the module.
Traditionally, a pack would be built with identical cells throughout. This new approach provides advantages beyond cost. If a battery needs servicing in the field and newer chemistries have been developed since it was originally produced, a module with updated chemistry could be used. This is also beneficial over the long haul so that GM doesn’t have to stock service parts of old cells.
After the battery has reached end of life, the modules can be more easily reused in a mixed environment because the BMS can balance the output of the modules.
Within the module, cells can be mounted in either a horizontal or vertical orientation as needed for a particular application. This allows flexibility for use in different vehicle types. Modules with vertically stacked cells can be made shorter for a thinner overall pack height to use in cars. Meanwhile, for truck applications like the Hummer EV, two layers of modules with horizontally stacked cells can produce a pack of up to 200-kWh. With the cells now representing 80-90% of the cost of the pack, the total pack cost may now be less than $120/kWh, among the lowest in the industry.
GM has developed the Ultium battery system to be flexible for a range of applications with sizes ranging from 50 to 200-kWh. Smaller batteries for lower cost vehicles will be arranged with a 400V architecture and support for up to 200-kW DC fast charging. The larger packs for truck and high-end applications like Cadillac will use an 800V architecture and support 350-kW charging. Depending on the configuration and charge power, these batteries will be able to add over 100 miles of range in just 10 minutes.
Of GM’s upcoming EVs, only one has been shown publicly in its entirety, the Cruise Origin that we saw in January in San Francisco. We’ve also seen sketches of a Cadillac Crossover and a teaser image of the face of the GMC Hummer EV pickup. These are three incredibly disparate vehicles ranging from a small urban automated shuttle to a midsize luxury crossover to a high-performance full-size pickup truck. Yet despite their differences, they all share basic technology from GM’s new BEV3 toolkit.
In total, GM is planning 19 different combinations of battery packs and motors across this vast array of vehicle types. That compares to over 550 different engine and transmission combinations available on the current GM lineup.
Over the course of the coming weeks and months we’ll finally get to see more of these promised EVs from GM. First up will be the Cadillac Lyriq, the crossover that was teased in January 2019. The Lyriq will be shown publicly in early April followed by the Hummer EV in May. The Lyriq is planned to launch in China in mid-2021 and in North America early the following year. We’ll also be getting a look at new EVs from Chevrolet and Buick.
A new version of the Bolt will go on sale late this followed by a crossover based on it next summer. While the Bolt gets significant visual updates and an upgraded interior, it won’t yet be getting the Ultium battery. That will have to wait until the full generational change. The crossover known as the Bolt EUV will be the first non-Cadillac model to add Super Cruise.
At the event, we were shown 11 different EVs that GM will be launching in the coming years. In addition to the Cruise Origin and the two Bolt variants, we also saw the Cadillac Lyriq, the Hummer SUV and SUT, a full-size Cadillac SUV, a midsize Chevrolet crossover and midsize and compact Buick crossovers. The event wrapped up with the reveal of the Cadillac Celestiq, a new flagship sedan. The Celestiq will be a hand-built four-door, fastback sedan with styling quite unlike anything ever seen from Cadillac.
In addition to the vehicle technology, GM is also following a similar strategy to Ford and other automakers to make charging less of a hassle. A new Energy Assist feature was recently added to the myChevrolet smartphone app to help drivers find available chargers with real-time data from EVGo and Chargepoint. Drivers can also link there EVgo account to pay for charging sessions right through the same app. This integration isn’t as extensive as Ford is doing through Fordpass, but it’s a start. GM has offered workplace charging at its facilities since the Volt went on sale in 2010, but this year it will be adding 3,500 more charging stations at plants and offices to enable more employees to go electric.
There is still a ways to go before GM is truly an EV company, but today’s announcement of the Ultium battery and more details on BEV3 vehicles is a big step down that path. GM CEO Mary Barra has targeted selling 1 million EVs annually by 2025 and they plan to be profitable on all of the BEV3 models.
Source: Forbes, 04/03/2020