Supercharching

Battery production

Life as we know it is inextricably linked with batteries. From smartphones and electric cars to grid stabilization for renewable energy power plants – batteries are at the heart of how we communicate, entertain ourselves, and drive a more sustainable future.

  

With so many stakeholders looking for more efficient batteries and the ability to produce on an industrial scale, the industry is experiencing change and innovation at an unprecedented rate. In 2020, 1.38 billion smartphones were sold worldwide. General Motors’ announcement in January 2021 that they would go “all-out electric” by 2035 is perfectly in line with the trend seen among car manufacturers worldwide as they accelerate their push for green mobility. To support grid stabilization, battery parks are being built all over the world with capacities of up to 1 Gigawatt – that equals the power produced by 3.125 million solar panels. These are impressive figures that have one thing in common: an insatiable appetite for batteries. Bühler’s continuous mixing technology for battery slurry plays a key role.

 

“It’s an exciting time to be in the battery business. The market is so dynamic, there are new players and innovations popping up everywhere, and it shows no signs of slowing down,” says Adrian Spillmann, Director Market Segment Battery Solutions at Bühler. “Electro-mobility is really picking up speed – increased customer demand, tighter government regulations to reduce the carbon footprint, technological improvements, and the rapidly growing infrastructure are converging to form a perfect storm.” 

It’s this kind of demand anticipated by Bühler’s Grinding and Dispersing business area – one of Bühler’s three business areas in the company’s Advanced Materials business, with a turnover of nearly CHF 100 million – when it set up its Battery Solutions business around 10 years ago. Based on its proven twin-screw extruder technology for the food and feed industry, Bühler invented a new continuous mixing process for battery slurry. Instead of using cereals and pet food, the engineers started running trials with electrode slurries. “We said to ourselves: ‘Let’s go for it.’ We have the technology, and we have the process know-how to improve battery slurry production in terms of speed, flexibility, quality, and quantity,” says Spillmann.

Adrian Spillmann, Director Market Segment Battery Solutions at Bühler. Adrian Spillmann, Director Market Segment Battery Solutions at Bühler.
The challenges are huge, but so are the opportunities. At the end of the day, it’s all about living up to our promise of ‘innovations for a better world’.

Adrian Spillmann, Director Market Segment Battery Solutions at Bühler

A quantum leap

The quality of the electrode slurry is essential for the performance and energy density of a lithiumion battery. Traditionally, slurries are produced in large vessels which do not necessarily meet the requirements for large-scale production in terms of total cost of ownership. The process is also very inflexible. If a batch does not meet the requirements, it is either disposed of, reworked, or used for inferior products. While the production of large batches takes several hours, the continuous mixing process requires only a few minutes. “We use a rotating twin-shaft mixer to combine the necessary process steps such as pre-mixing, homogenizing, dispersing, and degassing into a single, continuously running unit,” says Spillmann.

Thanks to this continuous mixing process, the manufacturer can intervene at any given moment should the results not meet the requirements. What counts is that the improved mixing process significantly increases battery performance. It also reduces investment costs, and the energy costs are much lower, too. Lastly, the new process takes up much less space, and fewer rejects are produced. This process took years to develop. 

In 2017, the opening of the first production plant at Lishen in Suzhou/China marked a milestone in the industrial-scale production of battery slurry. Yi Liu works as an engineer for the Chinese battery manufacturer Lishen. He developed the technology with the Bühler team and said during the inauguration ceremony: “This solution will completely change the battery industry. It is a historic moment, a revolution.”

Watch the video about our Battery Application Lab.

Consistent quality is key

Four years later and 9,000 kilometers away, Valentin Dolder and Adrian Spillmann look at the latest data from Bühler’s Inline Quality Control expert system, QuaLiB. It enables inline monitoring and controlling of process parameters. “Continuous quality control is pivotal in the production of battery slurry. Before we introduced QuaLiB, manufacturers would lose time and money by physically taking samples, running offline measurements in a lab, and noticing quality issues too late. By using the QuaLiB system, the production yield can be increased,” says Dolder.

 

Valentin Dolder, Technologist Market Segment Battery Solutions at Bühler. Valentin Dolder, Technologist Market Segment Battery Solutions at Bühler.

After successful trials in China and Switzerland, Dolder and his team are now running tests with a major carmaker in Germany. For Dolder, every battery producer that uses Bühler’s continuous mixing process should include QuaLiB in their process. “The system is fully integrated in the process, and automatically identifies the product quality in real time.” 

Moreover, producers enjoy complete transparency of their process and materials, which becomes more and more important as entire value chains are having to function like clockwork amid rapidly increasing demand.

 

The system is fully integrated into the process, and automatically identifies the product quality in real time.

Valentin Dolder, Technologist Market Segment Battery Solutions at Bühler

Insatiable global demand

Asia’s leading role in the industrial production of batteries started in 1991 when Japanese Sony and Asahi Kasei released the first commercial lithiumion battery. With electric cars taking over the roads and the increasing demand for battery parks, Europe is confronted with an infrastructure gap in relation to Asia when it comes to large-scale battery production. The European Battery Alliance (EBA) aims to close this gap to reduce Europe’s dependency on batteries from Asia, and has the backing of the European Union’s members.

In January 2021, the European Commission approved a EUR 2.9 billion public support package from twelve Member States for a second Important Project of Common European Interest (IPCEI) to support research and innovation along the entire battery value chain. From raw and advanced materials to battery cells, battery systems, and recycling and sustainability, Europe aims to make up some of the ground lost over the last decades.

It is also proof of the strategic importance of batteries. A 2019 study by the World Economic Forum (WEF), the Global Battery Alliance (GBA), and McKinsey analysis projects that global battery demand will grow by a factor of 14 between 2018 and 2030 – from 184 Gigawatt hours (GWh) to 2,623 GWh. The bulk of global demand will come from electric mobility at 2,333 GWh, while energy storage and consumer electronics will require 221 GWh and 69 GWh respectively.

Strategic importance

A look at the supply and demand by region reveals why the European Union is investing heavily in building up its own production infrastructure. In 2030, almost 43 percent of demand will come from China at 1,122 GWh, and Europe’s appetite for battery power will amount to roughly 17 percent at 443 GWh. 

The study’s authors expect global cell production capacity to reach 860 GWh by 2025, of which 60 percent will be from China. This leaves a gap of 1,700 GWh to meet the anticipated demand in 2030 and could result in supply shortages for European car manufacturers. These projections underline the global urgency of ramping up production capacities and avoiding dependencies on all sides. 

Spillmann experiences the gear shift in the car industry on a daily basis. “All major car producers are betting on electric vehicles. The internal combustion engine has been at the heart of their production lines for decades, and now they’re all rushing to build up capacities to make their own batteries.”

The announcement by German car manufacturer Opel on July 8, 2021 underlines the speed with which change is happening. The company said it would stop producing cars with internal combustion engines in Europe by 2028, setting one of the most ambitious targets in the industry.

Bühler’s continuous mixing process ensures an optimally homogenized electrode slurry. Bühler’s continuous mixing process ensures an optimally homogenized electrode slurry.

Science at the heart of innovation

In his lab in Dübendorf in Switzerland, Corsin Battaglia analyzes new battery materials with his colleague. He is the Head of the Laboratory Materials for Energy Conversion at the Swiss Federal Laboratories for Materials Science and Technology (Empa), and in his role, he knows just how fast the heart of the battery industry is beating these days. “It’s a very dynamic industry, and the speed with which electric mobility is gaining momentum drives innovation at an unprecedented level,” he says.

Battaglia and his team conduct research projects and collaborate with industry. “We are developing new materials and processes for next-generation batteries by looking not only at fundamental materials science issues, but also at how new materials and processes can be transferred to industry.”Battaglia and his team conduct research projects and collaborate with industry. “We are developing new materials and processes for next-generation batteries by looking not only at fundamental materials science issues, but also at how new materials and processes can be transferred to industry.”

 

It’s a very dynamic industry, and the speed with which electric-mobility is gaining traction drives innovation at an unprecedented level.

Corsin Battaglia, Head of the Laboratory Materials for Energy Conversion at Empa

So, what exactly are Battaglia and his team focusing their research on? “From a material perspective, lithium metal is a very interesting anode material for next-generation batteries. Compared to today’s lithium-ion batteries with graphite anodes, batteries with lithium-metal anodes can store almost twice the amount of energy per charge,” he says. This would extend the reach of electric vehicles and improve the storage capacity of battery parks. “One major issue for lithium-metal anodes is the tendency to form so-called lithium-metal dendrites, which can provoke a short circuit in the battery. That is where material science comes into play. New solid electrolyte materials are promising to prevent dendrite formation and enable next-generation solid-state batteries.”

Another element keeping researchers around the world on their toes is cobalt. Sixty percent of cobalt is found in the Democratic Republic of Congo (DRC), and the extraction methods have a significant impact on society and the environment. There are alternatives, but their energy density remains a challenge. “Lithium iron phosphate (LFP) for example is cobalt free, but its energy density is lower,” says Battaglia. “We are developing cathode materials based on manganese and titanium, which result in high energy density, but still suffer from relatively low stability when cycled in a battery.”

Empa is also investigating higher-level topics such as a circular economy for batteries. “While manufacturers need to produce millions of batteries as soon as possible, we’re taking a more holistic view and ask ourselves how we can expand the life cycle of batteries and contribute to sustainability,” Battaglia explains. “For example, we are collaborating with the Swiss company Kyburz to develop a novel energy-efficient aqueous recycling route for lithium-ion battery cell assembly.” 

At the Battery Application Lab, Spillmann looks to the future with optimism. “Batteries will be at the heart of the green transformation in the mobility and energy industry. Thanks to increased investments and a real sense of urgency, innovation and collaboration is happening on a scale we’ve never experienced before. With our continuous mixing technology, we have a proven and sustainable solution for our customers that will allow them to ramp up production capacities and ready themselves for the increasing demand.” 

 

Corsin Battaglia and postdoctoral researcher, Marie-Claude Bay in the laboratory of the Swiss Federal Laboratories for Materials Testing and Research (Empa). Corsin Battaglia and postdoctoral researcher, Marie-Claude Bay in the laboratory of the Swiss Federal Laboratories for Materials Testing and Research (Empa).

Bühler is not resting on its laurels, but powering entire industries is a task too big for anyone to solve alone. With the help of its vast network of industrial partners, scientific institutions, and thanks to its drive for innovation, Bühler’s Grinding and Dispersing team is taking up its responsibility in this quest. Spillmann concludes: “We will continue to innovate together. The challenges are huge, but so are the opportunities – we’re proud to do our part. At the end of the day, it’s all about living up to our promise of ‘innovations for a better world’.”

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