A lithium-ion battery works by moving lithium ions back and forth between two parts called the anode and the cathode.
When the battery is providing power, the lithium ions move from the anode to the cathode, creating a flow of electricity that provides power. When charging the battery, the ions move back to the anode, getting ready to provide power again. This back-and-forth movement of ions is what makes the lithium-ion battery reusable and powerful. The following animation depicts how a lithium-ion battery works is courtesy of the U.S. Department of Energy.
Due to their high energy density, rechargeability, and long life span, lithium-ion batteries can power various devices, from smartphones to electric vehicles (EV). Have you ever wondered how a lithium-ion battery is manufactured and ends up in the EV you are driving? Continue reading to learn how a lithium-ion battery is manufactured
The production of lithium-ion batteries involves sophisticated chemical, mechanical, and electrical processes to ensure safety, efficiency, and performance. Let’s examine the complex process of lithium-ion battery production, from raw material extraction to the final assembly of the battery cells. The following outlines the key stages of creating a lithium-ion battery, including material preparation, cell assembly, and quality control.
Step 1: Raw Material Extraction & Preparation
The first step in lithium-ion battery production is the extraction of raw materials. According to the National Renewable Energy Laboratory, “Critical raw materials used in manufacturing [lithium-ion] batteries include lithium, graphite, cobalt, and manganese.” Inside the lithium-ion battery are the anode and cathode electrodes which allow for the flow of electric charge. The anode is often constructed from a carbon-based material such as graphite. The cathode is made from metal oxides such as lithium, cobalt, and manganese.
Step 2: Active Material Synthesis
Material synthesis is the process of creating materials with specific properties and structures through chemical or physical means. Once the raw materials are extracted and prepared, the next step in lithium-ion battery production is synthesizing the specific electrode material through chemical reactions. This can involve mixing, heating, and cooling the base metals, adding lithium, graphite, as well as other binder materials as necessary.
Step 3: Electrode Manufacturing
Manufacturing the electrode is the third step, which involves slurry preparation, coating and drying, and calendering. In slurry preparation, the active materials for either the anode or the cathode are mixed with a solvent and binder to create the slurry. The slurry is then coated onto a metal foil (typically copper for the anode and aluminum for the cathode) and dried in a controlled environment to remove the solvent. Finally, the coated foils are passed through rolls to achieve the desired thickness and density. This is called calendering.
Kadant’s Role
This is the point in the lithium-ion battery manufacturing process where Kadant steps in to improve the process and end product. As mentioned above once the slurry, coating, and drying takes place, the coated foils are passed through a series of rolls called calendering. Kadant supplies a unique, compact, continuous roll cleaner to keep the rolls free of contaminates. To learn more about the VeriLite™ roll cleaner assembly and its use in lithium-ion battery production, check out the article, “Kadant Solutions Plays a Critical Role in Lithium-ion Battery Production.”
Step 4: Cell Assembly
Lithium-ion battery cells come in various forms, including cylindrical, prismatic, and pouch cells. Depending on the cell design, the anode and cathode foils are stacked with separators in between or wound into a jelly roll. This is sometimes called electrode stacking or winding. Next, electrolyte filling takes place when the cell is filled with an electrolyte solution that facilitates the movement of lithium ions between the anode and cathode. Finally, the cell is sealed to prevent leakage and contamination.
Step 5: Cell Formation & Aging
Formation involves charging and discharging new cells to activate the electrolyte solution and form a solid electrolyte interphase (SEI) on the anode. This is crucial for the battery's longevity and performance. Cells are stored for an aging period to stabilize performance characteristics.
Step 6: Cell Module & Pack Assembly
The energy density found in lithium-ion technology has enabled batteries to fit in smaller and smaller places. This unlocks creativity within companies that never before seemed possible. Cells are assembled into modules and packs with virtually no dimensional constraints. Battery management systems (BMS) monitor and control performance, ensuring safety and efficiency.
Step 7: Quality Control & Testing
Lithium-ion batteries are everywhere in society; mobile devices, electronics, electric vehicles, infant toys, the list just keeps going. The same energy that makes these so vital to consumer products also demands tight adherence to manufacturing tolerances. To ensure compliance, rigorous quality control and testing are conducted throughout the production process. These steps include material inspections, in-line quality during the manufacturing process, performance testing, and safety testing.
The production of lithium-ion batteries encompasses a wide array of processes, from the extraction of raw materials to the assembly and testing of finished cells. Each step requires precision and care to produce high-quality, safe, reliable batteries. As the demand for these batteries continues to grow, innovations in production techniques, materials, and recycling are crucial for meeting global energy storage needs sustainably.
