ASK THE EXPERT: Advanced Lithium Processing Makes for Better Batteries

Lithium-ion batteries power many of today’s hottest technologies, including electric vehicles, energy storage, and portable electronics. Manufacturers of the rechargeable batteries are not only experiencing soaring demand, but also consumer pressure to improve their products. For the processors of raw materials within those batteries, this means constantly refining and improving their systems and processes.

Organizations that produce battery materials, or build chemical factories to make them, often turn to experts to strategically design their processing systems, test their materials, size and specify their equipment, and fabricate the equipment to the highest standards to help the organizations be successful in their goals. Christopher Paulsworth is the manager of the chemicals, minerals, and metals division at Hosokawa Micron Powder Systems, which develops equipment and designs processes for factory applications such as battery materials manufacturing. We asked for his thoughts on the predominant battery material trends and technologies driving the battery industry today.

What are battery manufacturers looking for now, and why are specialized technologies needed to address these needs?

A: Battery manufacturers see customers requesting smaller, lighter, cheaper, and more resilient batteries. For instance, in the EV market, people want affordable EVs that hold a charge longer, drive farther, and charge faster. It’s not a direct link but this tends to lead to requests for finer products, with less ultrafine dusts and rounder particles, in addition to lower energy consumption and higher process yields.

For the material manufacturer to obtain finer, cleaner, and rounder products with less loss and energy input, we can supply our specialty powder processing equipment. And with the investment sizes of these plants, using equipment from a trusted manufacturer with equipment that has been in the field for many years, and a proven record of uptime, is also key to lower costs. We focus on the two main components within the battery: the cathode and anode.

What type of technology is used for the cathode?

A: On the cathode (positive) side of the battery, we manufacture equipment to micronize both the lithium feedstocks and the cathode materials. The Air Classifying Mill (ACM) grinds the lithium feedstocks, producing battery-grade carbonate and hydroxide, while using less energy than jet mills and meeting the particle size and purity requirements.

The cathode material is closer to the end product and more sensitive. An ACM with a fully wear-protected and mostly ceramic lining can reach the required particle size distribution (PSD) while minimizing material pickup. On the other hand, the AFG Fluidized Bed Jet Mill with particle-on-particle micronization that uses air is the way to ensure minimal pickup of impurities, though at higher energy and installation costs.

What is graphite rounding and how does it benefit the battery industry?

A: The battery’s anode holds the electrons when the battery is charged. One of the main goals for this side is to hold as many lithium ions as possible. The material is measured based on the charge per volume and less so on the charge per weight. We provide processes that allow the end user to pack the anode material in, improving the quality of the battery.

The rounding, which comes later in the process, is where the particles are lightly milled and deformed to make them rounder. The rounder particles pack better, and we do it with the Alpine Particle Rounder (APR). There is also a preliminary grinding step with the ACM and dedusting after micronization and rounding with our specialty line of Turbo Twin Double (TTD) classifiers.

These processes increase the bulk density of the material. The yield after dedusting and rounding are the keys to the cost and quality equation that we present to customers

How does lithium carbonate impact the development of batteries?

A: Lithium carbonate is one of the two main types of lithium feedstocks for cathodes. Lithium carbonate and lithium hydroxide are each used for the synthesis of the active cathode materials. The consistent and controlled micronization of these feedstocks supplies a building block to facilitate the development of future materials.

How do companies like Hosokawa Micron Powder Systems support the production of lithium-ion batteries?

A: Our materials processing equipment has been proven to last more than 30 years in the field, in harsh industrial environments, under constant use, and all with minimal maintenance. This year marks our 100th anniversary, which indicates the high level of quality and service our customers have come to expect.

Understanding the specs that manufacturers need now and may look for in the future is crucial to delivering the proper equipment and processes. Strong aftermarket and service teams with a clear understanding of the equipment, including the variety of sizes and construction materials, know how to find ways to tweak or improve the systems as requirements increase.

We also have a Test Center where we can test customer material in our facility to prove their system is going to work and what the results will be, before scaling it up to industrial size. The center also gives customers access to milling materials that they can use for their development.

A current opportunity is finding ways to help our customers recycle or downcycle battery materials, because if we can separate it out, it could be a valuable feedstock. Meeting demand solely by mining fresh lithium and graphite, or producing synthetic graphite from petroleum byproducts, is unsustainable, so we are exploring all the technologies in our solution suite to see how they might support recycling.

As appeared in the Ask the Expert section on ProcessingMagazine.com, November 2023.