With the rise in demand for electric vehicles (EV), the demand for lithium-ion batteries has also skyrocketed. However, it is becoming apparent that the rate of battery production is limited by the available supply of raw materials, especially for the metal oxide cathode. To supplement the supply chain of key metals produced by mining, the U.S. Department of Energy’s Vehicle Technology Office has created the ReCell Center as the first R&D consortium to help spur new recycling technologies for spent EV batteries. What’s more, the Biden Administration’s Bipartisan Infrastructure Law has identified battery recycling as a focus area to help bolster our domestic supply of battery materials.
Battery Cathode Production R&D at Storagenergy
Storagenergy Technologies, a technology development company based in Salt Lake City, Utah, has used grant funding awarded from the U.S. DOE to develop an advanced manufacturing method for battery cathode synthesis and recycling. This new method, dubbed Flame-Assisted Spray Technology (FAST) has the potential to generate cathode powders faster and at lower cost compared to traditional co-precipitation methods.
In co-precipitation, metal salt precursors are dissolved in solution, then gradually fed into a Continuously Stirred Tank Reactor (CSTR). The pH of the solution is adjusted to slowly precipitate the products in a batch-wise operation. The precipitated powders are collected, mixed with a lithium salt, and baked at high temperature for many hours to obtain the final product.
By contrast, spray-drying or spray-pyrolysis synthesis methods are comparably simpler, and should be capable of continuous large-scale production of product powders. In this method, metal precursor salts are dissolved in a solution, which is then passed through a spray nozzle to form thousands of tiny droplets in a heated chamber. As the solvent in each droplet dries, tiny solid particles are formed much faster than the co-precipitation method. In Storagenergy’s FAST process, they have added a flame-assisted heating zone to their reactor that allows them to significantly shorten, or even eliminate the post-spray heating time required to obtain the final product, thereby reducing cost and saving time.
In 2021, Storagenergy completed a custom-built pilot reactor to demonstrate the proof of concept by producing NMC (LiNixMnyCozO2) cathode powder, the state-of-the-art in current lithium-ion batteries for EVs. They used this powder in prototype lithium-ion battery pouch cells, which are undergoing 3rd-party validation at Idaho National Laboratory. So far, cells are projected to cycle 500 times with 80% capacity retention, a promising result for preliminary tests. The FAST process is expected to be compatible with a variety of cathode chemistries, including LFP (LiFePO4), a cheaper alternative that is projected to replace a significant portion of NMC-batteries in the future.
Dr. Feng Zhao, CEO of Storagenergy, said:
It is critical for the United States to curb our reliance on foreign countries for our domestic battery needs.
“By continuing to develop our FAST technology, Storagenergy hopes to contribute to the battery supply chain by enabling cost-competitive and high-throughput domestic cathode production.”
Battery Cathode Recycling R&D at Storagenergy
More recently, Storagenergy has demonstrated that the FAST process can also be used for direct recycling (and ‘upcycling’) of spent cathode materials. Once batteries have degraded after years of use in an EV, there are several strategies to recover the valuable metals for re-use. Most commonly, spent batteries are crushed and ground into a ‘black mass’, and strong acids are used to dissolve and recover the most valuable metals from the cathode, such as cobalt and nickel. Such ‘hydrometallurgical’ processes recover metals as low-value salt precursors, which then must be used to re-synthesize the high-value cathode material.
Alternatively, ‘direct’ recycling methods focus on recovering the cathode in its high-value form, rather than breaking it down to individual elements. The recovered cathode generally has lost a little lithium during its cycling life, so the recycling process requires a little bit of added lithium and a heating step to melt that lithium into the product. The recovered cathode can also be ‘upcycled’ by adding both lithium and nickel, for example, in order to create a product with superior properties to the original.
Storagenergy has developed methods to break down the recovered cathode into fine particles without damaging their valuable crystal structure, then coat those particles with metal salts for recycling or upcycling, and finally reform the product powder in their FAST reactor. This method enables a shorter heating time and lower cost to incorporate the added lithium or nickel, for example. Both their recycled and upcycled NMC materials are demonstrating promising cycle life in prototype lithium-ion battery pouch cells.
Storagenergy’s FAST recycling process substantially decreases energy, water, and greenhouse gas emission over the current recycling practices and increases lithium, cobalt, and nickel recovery yield to above 90% from recycling feedstocks. The modular design of the FAST reactor also lowers capital costs for installation and allows for flexibility for production capacity to expand with demand.
According to Zhao:
“We think this technology could be a real game changer in cathode recycling and upcycling. We are currently applying for additional grant funding and seeking interested investors to continue pilot demonstrations of our FAST-enabled recycling.”
About Storagenergy Technologies, Inc.
Storagenergy was founded in Salt Lake City, Utah in 2011, with a mission to develop solutions to next-generation challenges in energy storage, energy production, and environmental solutions. With their recent FAST process, Storagenergy strives to provide quality battery materials to mitigate the environmental impacts of battery manufacturing and also to secure the domestic supply chain for a robust clean energy transition. Their FAST reactor offers systematic advantages in costs, energy efficiency, and environmental protection by recycling and upcycling of end-of-life lithium-ion batteries within an optimized system.
CONTACTS
Storagenergy Technologies, Inc.
Investor Relations
Feng Zhao
investors@storagenergy.com
Thanks for staying up to date with Batteries News.
