Take up the charge

Batteries are ubiquitous. From smartphones to electric vehicles to entire large-scale storage facilities for renewable energy, life without rechargeable batteries is unimaginable. With governments, companies, and consumers accelerating the green transition to avoid the worst impacts of the climate crisis, multiplying production and increasing the efficiency of batteries will tip the scale in our favor.

Keeping track of the incredible pace of the green transition is a tough task. In February 2023, the European Parliament voted to approve a new law banning the sale of petrol and diesel cars from 2035 to accelerate the transition to electric vehicles. Meanwhile, the global renewable power capacity generated from wind and solar is expected to grow by 2,400 gigawatts from 2022 to 2027, according to the International Energy Agency (IEA). This amount is equal to the entire installed power capacity of China today.

In the United States, the Inflation Reduction Act (IRA) provides tax credits worth hundreds of billions of dollars for renewables until 2032 to move away from gas, coal, and oil as the country’s primary sources of energy. What connects these ambitious targets? Batteries, either in the form of power supply for electric vehicles, or as storage capacity for renewable energy sources. The required quantities are staggering, and the race to secure battery capacity is on, not least driven by geopolitical interests. 

The European Union (EU) acknowledged the widening technology and capacity gap between Europe and Asia – in particular China, Japan, and South Korea – and formed the European Battery Alliance (EBA) in 2018. By the end of 2021, 111 industrial battery projects were being developed across EU Member States, with more than 10 gigafactories for the production of battery cells. According to the EBA, the EU is set to meet 69 percent and 89 percent of its increasing demand for batteries by 2025 and 2030 respectively and should be capable of producing batteries for up to 11 million cars per year. It is expected to invest EUR 382 billion to create a self-sufficient battery industry by 2030.

Far away from the political commotion, Christian Hänsel puts on his lab clothes and safety equipment and heads to the Battery Application Center in Uzwil, Switzerland. He’s a Process Engineer in Bühler’s Grinding & Dispersing business and conducts trials to increase efficiency and sustainability in battery production. Hänsel and his team are at the very heart of this megatrend – their research, trials, and the battery factories they equip for customers might well decide how fast society can move away from fossil fuels.

“Our customers find themselves in a challenging situation. Demand is ever increasing, and with this comes a myriad of questions. The most urgent one is to find ways to establish battery production at industrial scale,” he says. That’s especially the case in Europe, where many players have been a little late to the party and are now faced with the task of making up lost ground on the Asian competition. Hänsel knows that his team is in a unique position thanks to the far-sighted research and development strategy at Grinding & Dispersing.

“In our Battery Application Center in Uzwil, we run concept trials together with customers on our lab-sized, twin-screw extruder with a 20-millimeter screw diameter, which allows for a capacity of 20 liters per hour. Our continuous mixing technology to produce battery slurry combines the basic operations of continuous raw material dosing, pre-mixing, kneading, fine-dispersing, and degas-sing in a single device. After the trials, we’re able to determine exactly the parameters needed for production on an industrial scale for our customers.” In addition to the application center in Uzwil, Bühler’s Grinding & Dispersing business runs a pilot-scale extruder with a 30-millimeter screw diameter and a capacity of 100 liters per hour in Wuxi in China.

Powerful impact

The savings potential increases dramatically when scaling effects unfold their magic. “Around 70 percent of battery costs are attributed to raw materials. The production costs in gigafactories make up 20 to 25 percent, while around 5 percent are other costs. That’s why we see the biggest lever to bring down costs and accelerate the green transition in the industrial production space,” says Hänsel.

According to his team’s research, the specific energy consumption to produce 1 ton of battery slurry using batch mixing technology is 224 kilowatt hours per ton (kWh/t). Bühler’s continuous mixing technology consumes four times less energy; a mere 56 kWh/t, and a staggering savings potential amid rising energy costs. Combined with a high degree of automation and improved yield, the total cost of ownership is further reduced, which lowers the entry barrier for new players on the market.

Demand is increasing, and with this comes a myriad of questions. The most urgent is to find ways to establish battery production at industrial scale.

Christian Hänsel, Process Engineer Grinding & Dispersing at Bühler

Never standing still

Resting on their laurels, however, is not in the DNA of Grinding & Dispersing. At the end of March 2023, the team hosted 50 guests from 27 companies and 13 countries to introduce and discuss a more sustainable means of battery production: dry battery electrode (DBE) technology. Currently, the components are mixed into a liquid paste that is put on a foil and dried – a process that is time- and energy-consuming, but also requires toxic solvents which cost money and impact the recycling of batteries.

The DBE technology, on the other hand, is based on the ability of polytetrafluoroethylene (PTFE) to fibrillate under shear. A polymer fiber network is built up in which the electrode components are immobilized. A soft composite structure is discharged from the extruder and the flaky product can be pressed into an electrode layer and subsequently laminated to the current collector foil, yielding the final electrode structure.

This promising technology resonated well with the guests from academia, research institutions, and industries such as car manufacturers looking to ramp up their own battery production. “We had fantastic keynotes and discussions on DBE. This encourages us to continue our research in this technology and develop a path towards industrial production with our partners,” explains Hänsel as he heads back to the Battery Application Center to prepare the next trial. Given the pace in the race for independence and supremacy in battery production, it seems almost certain that he’ll be spending most of his time doing what he enjoys most: experimenting, collaborating, and discovering new ways to supercharge the green energy transition.

About Bühler’s innovative solutions for the efficient production of electrode active materials and electrode slurries:

  • The continuous mixing technology consumes four times less energy than batch mixing for 1 ton of battery slurry – a mere 56 kWh/t.
  • The energy efficiency of the continuous mixing technology combined with the high degree of automation and improved yield reduces the total cost of ownership.
  • Production makes up 20% to 25% of production costs of batteries – a huge lever for producers to bring down costs through innovative production technologies.
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