Can 3D Printing Finally Make Solid-State EV Batteries Practical?

San Jose-based 3D-printing startup Sakuu (initially KeraCel) reckons it might have lastly cracked the code and found the holy grail that might ultimately make solid-state batteries a sensible actuality in the whole lot from microelectronics to huge electrical automobiles. We defined the numerous virtues of solid-state batteries right here, together with their inherent hearth security, insusceptibility to freezing, improved power density, and so on. Sakuu’s advance is as a lot a 3D-printing breakthrough as it’s certainly one of battery chemistry, and its Swift Print battery know-how guarantees to allow manufacturing of batteries in customized kind components that will look nothing like at the moment’s pouch, prismatic, or cylindrical cells.

Stable-state battery articles typically examine efficiency with “lithium-ion” chemistry, which at all times means, generically, the prevailing Li-ion chemistries that make use of liquid electrolytes. Sakuu’s battery additionally options lithium-ion chemistry (versus lead-acid or zinc-air for instance), with its sub-category being lithium steel, versus the most well-liked nickel-manganese-cobalt (NMC) or lithium-iron-phosphate (LFP) for instance. This implies the anode is pure lithium.

As for the electrolyte—which is essential to any lithium-based battery’s long-term well being and security—that is nonetheless a jealously guarded secret, regardless of the safety of 80-plus patents. What we do learn about what separates the anode and cathode on this 3D printed solid-state battery, is that it was developed at Harvard’s John A. Paulson College of Engineering and Utilized Science and consists of differing supplies of various traits designed to manage and comprise the lithium steel filaments or “dendrites” that may kind on the anode, notably throughout quick charging, threatening to pierce the separator layers and short-circuit the battery.

The idea makes use of a binder-jet method developed by MIT, through which powder particles are deposited after which a liquid agent is utilized to treatment them. On this means Sakuu’s Kavian course of can mix bulk deposition with binder-jet utility of the curing agent to kind a thicker layer, possibly 25 microns thick. Then the identical tools can come again and apply a metallic present collector that’s only a couple microns thick, utilizing metal-jet deposition (a human hair measures 70 microns thick).

The Kavian platform can print ceramic, glass, metals, and polymer in a single layer—although the corporate has but to disclose precisely which supplies go into the 3D printed stable state battery. The method can also be designed to include artificial-intelligence high quality checks of each layer, to reduce defects and scrappage. And the method inherently reduces waste by solely making use of crucial materials and recycling any extra proper contained in the machine.

3D printing is vital to the success of Sakuu’s solid-state battery, as a result of one of these battery is sort of a layer cake, through which the layers should be extraordinarily skinny. This makes them laborious to deal with, and making certain a steady bond between them with none liquid is hard. Utilizing a 3D printer to deposit every layer instantly on the one beneath eliminates this drawback. One other particular sauce/enabler is Sakuu’s personal help materials referred to as PoraLyte. This materials may be strategically deposited wherever a channel or void is required, as a result of it burns away throughout a sintering course of. Compatibility points can come up when layering dissimilar supplies, however Sakuu has an entire crew of supplies scientists dedicated to resolving and stopping such issues.

With the Sakuu Kavian course of, uncooked supplies enter the machine and functioning batteries come out, passing by vastly much less tools. Relative to at the moment’s roll-to-roll battery manufacturing course of, for a given output, Sakuu believes this strategy can scale back manufacturing facility footprint by 44 p.c, decrease capital expenditure by 23 p.c, slash the variety of operations by 69 p.c, leading to a complete discount in manufacturing value of 33 p.c. A single 30-foot-long machine just like the one pictured above is anticipated to have the ability to produce 40 mWh/yr value of batteries (about 500 particular person EV’s value), incorporating all deposition and inspection steps to show uncooked supplies into working batteries.

Sakuu’s said purpose is to ship double the power density at 30 p.c much less weight than prevailing lithium-ion chemistries. And whereas the corporate claims its Kavian 3D printing course of may be utilized to different battery chemistries, inherently bettering power density on the order of 10-15 p.c (by eliminating wasted area within the battery), the lithium-metal design in dialogue right here is at present constructing out at 800 watt-hours per liter. The corporate sees a pathway to 1,200 Wh/l however notes that cycle-life can lower at larger densities, so if longer life is the purpose, a extra modest power density might make extra sense. The lithium-ion batteries powering at the moment’s EVs sometimes common round 350-500 Wh/l by comparability.

An as but unexplored alternative is the liberty of form-factor proposed by 3D printed batteries. Final 12 months we explored the potential for incorporating battery supplies right into a car’s physique construction. Sakuu’s Kavian course of for producing Swift Print batteries definitely looks as if one other potential enabler of this idea, and when the battery’s mass is serving a twin function that might in any other case be carried out by one other materials, it is not a burden to the propulsion system.

Maybe quickly, when you’re out there for an electrical two-wheeler. Sakuu is not able to disclose any of its shoppers, however one of many firm’s backers is Musashi Seimitsu, which produces bike gearboxes and gearing for EV discount transmissions, and the corporate has admitted an e-bike of some kind might be its first mobility utility. The corporate additionally disclosed to MotorTrend that it seems to be the primary to have efficiently 3D-printed a fully-functioning battery with customized shapes and sizing.

Sakuu’s facility in San Jose has additionally entered restricted manufacturing of cells for testing and verification functions and can quickly start transport these to undisclosed shoppers in automotive, mobility, aerospace, and industries starting from IoT units to medical tools. The corporate has retained the companies of Porsche Consulting to assist design gigafactories for industrial manufacturing of 3D-printed lithium-metal and solid-state batteries, and it is introduced a partnership with NGK to supply ceramic supplies. Sakuu isn’t alone. A German firm referred to as Blackstone Assets AG additionally purports to be engaged on 3D-printed batteries, with a solid-state variant within the works. We promise to maintain you posted on all the most recent developments.