April 27, 2022
Ascend Elements uses microstructure engineering to transform critical elements from recycled lithium-ion batteries into new, custom-made cathode materials
WESTBOROUGH, Mass.—A New England company is bringing advanced materials engineering to the recycling industry via a process that delivers custom-made battery materials to precise customer specifications.
Ascend Elements shared details of its Hydro-to-Cathode™ process technology in a press release, explaining how the company transforms critical elements from recycled lithium-ion batteries into new cathode materials that are said to rival or exceed the performance of cathode materials made with virgin metals.
The Westborough company said it can make custom-made battery materials to precise customer specifications by engineering the composition and microstructure of lithium-ion cathode particles during the direct precursor synthesis phase of its Hydro-to-Cathode process. Its Hydro-to-Cathode technology directly synthesizes new cathode active materials from spent lithium-ion cells more efficiently than traditional methods, the company said, resulting in reduced cost, improved performance, and lowered GHG emissions.
“Depending on the intended application, battery manufacturers require cathode active materials with different nickel, cobalt, and manganese concentrations,” said Eric Gratz, Ph.D., co-founder and CTO of Ascend Elements, in the release. “They may need battery material with a specific particle size, crystallinity, or porosity to meet their requirements. These adjustments in the elemental composition of the cathode material can make a huge difference in the energy density, safety, power, cycle life and overall performance of batteries.”
Battery chemistry and elemental composition of a lithium-ion battery are largely defined by the cathode active material used in the battery. A light-duty passenger EV battery optimized for weight and range, for example, will require a different cathode material than a commercial vehicle lithium-ion battery designed for power and durability.
Similarly, cathode material to be used in a power drill will not meet the same specifications as battery material meant for a laptop. The variety of battery chemistries is as varied as the many battery applications that exist, from massive utility grid energy storage systems (ESS) to handheld smart phones, the company said in the release.
“When it comes to recycling used lithium-ion batteries and transforming those critical elements into new cathode material, it doesn’t matter what type of lithium-ion battery is recycled,” Gratz said. “The battery chemistry at the start of the process has no impact on the type of new cathode material we can make from it. If the feedstock is a lithium-ion battery, we can transform it into the latest type of cathode.”
According to Ascend Elements, it can recycle a 10-year-old battery from a first-generation EV and break it down to an aqueous solution containing lithium, nickel, and cobalt atoms. It can then rearrange those atoms into the newest type of cathode active materials, from NMC 811 to NMCA or any other lithium-ion battery chemistry, the company said.
The incoming feedstock can even be a mixture of different lithium-ion battery types and elemental compositions, including used batteries from old EVs, laptops, cell phones, scooters, and power tools. Even Gigafactory scrap and waste can be mixed in. There’s no need to sort batteries into different categories before recycling, according to the company.
“Our technology can customize and engineer cathode active material in many ways—from composition, particle size, and distribution to crystallinity, morphology, and porosity—all tailored to specific customer requirements,” Gratz said.
The process was reportedly shown to enhance performance of batteries made with recycled materials. A peer-reviewed study published in the scholarly journal Joule found that battery cells made with Ascend Elements’ engineered cathode material had between 30 percent and 50 percent longer cycle life than traditionally made battery cells. The study also found an 88 percent higher power capability compared to traditional lithium-ion battery cells, according to Ascend Elements.
These performance improvements are attributed to the microstructure of the engineered cathode particles. Modified porosity of cathode particles improves lithium diffusivity, enabling lithium ions to travel through the cathode material more easily for higher power capabilities. The modified pore structure also provides strain relief, allowing expansion and contraction during charging and discharging without damaging the particles in the cathode, the company said.
“Our process is capable of other engineered characteristics beyond just porosity, including particle size, shape, and distribution,” Gratz said.
Beyond these material engineering capabilities, the Hydro-to-Cathode process is said to be much more efficient and environmentally friendly than traditional cathode manufacturing processes. It reportedly recovers 98 percent of the critical battery metals in spent lithium-ion batteries and manufacturing scrap. It also produces new cathode material at half the cost and 90 percent lower greenhouse gas emissions compared to similar cathode made with newly mined and refined metals, the company said.
“Microstructure engineering enables us to make sustainable battery materials that work as well as new,” Gratz said. “There’s no need to compromise on performance or value for sustainability.”