In an earlier post, Solving Battery Production Growth Challenges, we touched on the upstream, midstream, and downstream production from lithium mining to lithium battery production. Today, we’ll focus on the midstream production process. Again, Sung Heon Lee and I collaborated on the content of this post.
The midstream part of the lithium value chain involves manufacturing the Cathode, Anode, Electrolyte, and Separator. We will focus on the cathode, anode, and electrolyte in this series of posts. The process for making the Cathode, Anode, and Electrolyte is very similar. The process involves batch reactors and mixing.
The different ingredients are combined in a precise recipe for each of the components to meet the manufacturer’s specifications and quality requirements. After the cathode and anode components are reacted together, they form a slurry paste applied to a foil. The electrolyte is filled into the battery pouch to transport positively charged ions between the cathode and anode terminals.
There are many mixers in a typical plant that provide a lot of opportunity for automation including measurements, valves, and controls. As a plant increases capacity, it can’t just increase the size of the reactors and mixers without affecting quality. As plant staff adds more mixers and reactors, they also increase the number of measurement points. He is an overview of the key midstream processes:
Some key production challenges include:
- Optimizing production for flexibility in meeting customer requests for different battery component types and proprietary recipes
- Maintaining quality to meet or exceed specifications by limiting variation between batches caused by raw material variation
- Lacking view and insight into the progression of batch
- Maintaining reliable operations given the corrosive and abrasive materials flowing through the production process
- Keeping safe and environmentally secure operations by avoiding strong acid leaks.
One way to minimize risk to quality is by using consistent, integrated batch processes. DeltaV Batch manufacturing involves coordinating sophisticated sequencing across a plant while ensuring conforming to the recipe. DeltaV Batch Analytics provides a way to detect real-time process faults and anomalies that impact product quality or throughput. Using the most suitable measurement technology compatible with different fluid properties for anode, cathode, and electrolyte manufacturing are key. With improved control, analytics, and measurements we can help reduce batch variability that impacts quality, causes scrap and rework reduces profits, and negatively affects production schedules.
On the measurement side, controlling the material addition precisely to each reactor and mixer is critical. Micro Motion Coriolis meters are an ideal solution since they measure mass directly and density can be used as a quality check to ensure the correct ingredient was added. We also want to ensure anode and cathode slurry are at the correct viscosity. This measurement ensures that the correct thickness of the anode and cathode slurry is applied to the foil. pH measurement is critical for the cathode precursor and electrolyte quality. This is a difficult measurement because sulfides and hydrofluoric acid and few suppliers’ products can withstand this environment.
Conductivity is one of the most important measurements for the electrolyte. It must be in the correct range to ensure the transfer of ions between the anode and cathode, otherwise, the battery will not function at its designed specifications. It’s important to know the reactor level in the tank to confirm materials have been added correctly, and accurate level measurements with non-contacting radar level transmitters are well suited for the turbulent mixing tanks environment.
We’ll continue our closer look at the lithium midstream production process in future posts exploring process optimization, safe operations, and reliability improvements. Visit the links above for more on some of the technologies that drive operational performance improvements in your plant.