Second VW battery factory in Salzgitter?
Will solid-state batteries soon come from Germany?
VW is considering building a solid-state battery factory in Salzgitter, Lower Saxony, together with its U.S. battery development partner Quantumscape. Initially, a pilot plant is to be built where technicians will test the new production technologies. This pilot plant is to produce batteries with a total capacity of one gigawatt hour (GWh) per year.
Nothing works without taxpayers’ money
After that, VW and the battery specialist based in San Jose, California, want to expand production capacity to 20 GWh per year. VW will not make a decision on the construction of the factory until the end of 2021. In this context, the Wolfsburg-based automaker cautions that Salzgitter can only be considered as a location if the taxpayer helps in the form of government subsidies – otherwise Salzgitter would have no chance in international comparison.
Quantumscape convinces VW in laboratory tests
The battery company Quantumscape from San José, California, has now met the requirements to receive a further investment of $100 million (84.74 million euros) from its cooperation partner VW. The Californians have supplied solid-state lithium metal cells to VW and Wolfsburg researchers have successfully tested these cells in their laboratories.
More energy, less charging time
VW has thus invested a total of $300 million (253.93 million euros) in the American company so far. At the cell level, the solid-state batteries are expected to provide approximately twice the energy density of conventional lithium-ion batteries, with one kilowatt hour per liter. In addition, charging times are to be reduced considerably: At present, for example, the VW ID.4 charges energy for 450 kilometers of driving in 25 minutes – in the best case. This charging time is expected to drop to twelve minutes with the introduction of Quantumscape’s solid-state batteries in 2025.
Skeptics consider the start of series production of the solid-state batteries in 2025 to be unrealistic. They also complain that the costs are too high and that the entire cell is not fireproof.
Quantumscape believes problems can be solved
For Jagdeep Singh, the CEO of Quantumscape, the matter is absolutely clear: The current market share of electric cars is only two percent because the batteries are still too bad and too expensive: Too little range, not durable enough, too slow to charge and, in some cases, too flammable.
Singh believes normal improvements in current technologies are not enough. In his opinion, a quantum leap is needed. He believes this can only be achieved with new technology. Quantumscape’s credo: “The Future is solid” makes it clear which: Solid-state batteries.
Solid-state batteries with high potential
Battery researchers have long considered them to be the ideal solution because they make possible what has been the high potential of lithium batteries from the very beginning: the accumulation of pure lithium at the anode (negative pole). Maximilian Fichtner, Professor of Solid State Chemistry at the University of Ulm and Deputy Director of the Helmholtz Institute Ulm for Electrochemical Energy Storage, explains it this way: “The solid electrolyte is actually an aid. It is supposed to make the structure made of graphite on the negative pole side superfluous; you could then replace it with pure lithium. Indeed, the storage capacity of pure lithium is 2860 mAh/g. In current anodes, in which graphite stores the lithium, only 370 mAh/g is possible. That means that at the moment we are losing a factor of 8 on the negative pole side, so to speak, for safety reasons.”
Graphite has been used so far “because pure lithium in a liquid electrolyte forms needle-like structures on the surface when you keep adding and releasing it. These so-called dendrites grow into the cell, piercing boundary layers. This causes short circuits, the cell becomes hot, the electrolyte evaporates, the battery bursts and begins to burn. With the ceramic layer of the solid electrolyte, it is hoped to have a mechanical barrier against dendrite formation, and the negative pole side could be massively improved as described,” Fichtner said. In addition, solid (ceramic) electrolytes do not burn.
Anode without anode material
According to Singh, the QauntumScape cell does not require any lithium at the anode; previous lithium anodes have always required additional lithium instead of graphite, which does not absorb or release any lithium ions but only serves as a buffer. The difference in volume of the anode during charging and discharging must apparently be compensated for by the new electrolyte. Although it is ceramic, it is flexible. In a photo in the presentation, you can see how pliable the layer is.
The big secret of the QuantumScape cell is in the interface between the electrodes.
Jagdeep Singh also points out in his Dec. 8, 2020 presentation that without graphite and additional, “unproductive” lithium at the anode, a massive improvement in volumetric energy density is possible: while current lithium-manganese-cobalt (L-LMC) cells are around 500 Wh/l and nickel-Rich cells are 700 Wh/l, Quantumscape wants to reach 1,000 Wh/l. For e-cars, in which the batteries currently occupy the entire area between the axles with a height of 12 to 15 centimeters, this is a giant leap forward.
Quantumscape sees the gravimetric energy density of the new cell at around 400 Wh/kg, while current Li-NMC (nickel-manganese-cobalt) cells are around 250 Wh/kg and even the emerging nickel-Rich cells or those with silicon are unlikely to exceed 300 Wh/kg.
By the way, the materials at the cathode (currently lithium-manganese-cobalt or nickel) do not play a role in the presentations of Quantumscape – they are not even described in detail, but only as lithium metal. The big progress is the ceramic material of the electrolyte – which of course is not described in detail for a good reason.
At the end of the presentation, Frank Blome, head of VW’s Center of Excellence for Battery Cells in Salzgitter, also congratulates the team and confirms that Quantumscape cells have already been tested there as well. The results were very promising, he said. VW believes that the new cells are the beginning of high-range car batteries with great fast-charging capability.
Challenge of series development
Despite all the enthusiasm, Quantumscape also sees a long way to go, albeit a viable one now: they need to develop the single-layer prototype into a multilayer cell and on to mass production. And this is where VW comes in: In a partnership with the world’s largest automaker, mass production of solid-state batteries with a capacity of 20 GWh per year should be possible from 2024 to 2025.
VW has invested a total of $300 million in Quantumscape, while the battery company has already raised a total of $1.5 billion in capital to date. By comparison, VW announced in November 2020 that it would invest 73 billion in research and development over the next five years, 35 billion of which would go toward e-mobility. VW last invested the equivalent of around 165 million euros in QuantumScape in June 2020.
Has VW thus secured the super battery?
That sounds like a smart decision. If the company can indeed equip masses of e-cars with solid-state batteries as early as 2025, which could then offer 50 to 100 percent range and charging times reduced by two-thirds. Fire hazards would also no longer be an issue.
Another key advantage for a mass manufacturer is that the solid-state batteries are also expected to be cheaper. Quantumscape claims that production costs would fall because anode material would no longer be needed and would no longer have to be processed during cell production.