_______ ____________________________________________________________________________ DEPARTMENT OF MANUFACTURING ENGINEERING FACULTY OF MECHANICAL AND MANUFACTURING ENGINEERING UNIVERSITY TUN HUSSEIN ONN MALAYSIA 86400 PARIT RAJA, BATU PAHAT JOHOR ______________________________________________________________________________ BDX 10902 MANUFACTURING TECHNOLOGY 1 INDIVIDUAL ASSIGNMENT 1 TOPIC: LITHIUM ION BATTERIES ______________________________________________________________________________ NAME: MUHAMMAD NAUMAN SALIK MATRIC NUMBER: AD200226 LECTURER'S NAME: PROFESSOR KAMARUDDIN BIN KAMDANI PROFESSOR NOOR HAKIM BIN RAFAI SUBMISSION DATE: 31st DECEMBER 2020 Abstract: The objective of this report is to introduce the backgrounds, importance of Lithium Ion Battery. To discuss the most effective manufacturing process and production lay out of the factory. To evaluate the quality assurances and quality control of the process along with the economical conditions of the industry with the advancement of technology. The report also discusses the future prospects in regards to the improvements that can be implemented in regards to quality management and to make the product more cost effective​. 1 Contents: 1. Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2. Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 3. Manufacturing Process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-15 a. Operating Principle. . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 b. Technological Development. . . . . . . . . . . . . . . . . . . . . .5-6 c. Electrode Manufacturing . . . . . . . . . . . . . . . . . . . . . . . 6-10 d. Cell Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-13 e. Cell Finishing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..14-15 4. Production Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 5. Factory Production Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 6. Quality Management. . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 17-19 a. Quality Assurance and Control. . . . . . . . . . . . . . . . .17-18 b. Future Prospects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 7. Costs and Economics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20-21 a. Cost Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20-21 b. Future Prospects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 8. Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 9. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 2 Background​: In the late 1970s, a team of global scientists started the process of advancing towards what would later become the Lithium Ion Battery, a type of battery that would with time power almost everything from portable electronics to electric vehicles to mobile phones. During the oil crisis of the 1980s, Stanley Whittingham, an English Chemist, who was employed by the Exxon Mobile, began exploring the idea of a new battery, one that would recharge on its own in a small duration of time, he believed the batteries development would lead the world to fossil free energy one day. Figure 1(a) Initially Stanley Whittingham decided to use titanium di sulfide and lithium metal as the electrodes, but the combination was volatile. Due to several failed attempts for the combination to work, Exxon put the experiment on hiatus. In 1980s John B. Goodenough, a professor at the University of Texas, Austin, experimented using lithium cobalt oxide as the cathode instead of titanium di sulfide, which doubled the batteries energy potential. Figure 1(b) 3 Some years later, Akira Yoshiko of Meijo University in Nagoya, Japan, decided to make another altercation to the design, he used carbonaceous material namely petroleum coke, resulting in a revolutionary change, not only was the new battery tremendously safer without the lithium metal but also the performance of the battery became stable, resulting in the first successful prototype of the lithium ion battery. Figure 1(c) Uses​: Lithium ion Batteries have a very long list of real world applications, which include: ● Emergency Power Backups or UPS( Uninterruptible Power Supply). ● Reliable electric power for vehicles. ● Efficient and lightweight aquatic performance. ● Solar power storage. ● Alarm systems in remote areas. ● Portable power banks. 4 Manufacturing Process: ● Operating Principle: The manufacturing of Lithium Ion Battery is compromised of three main processes: 1. Electrode Manufacturing 2. Cell Assembly 3. Cell Finishing Figure 2(a) The electrode manufacturing and cell finishing are mostly autonomous processes that are not affected by the cell type, while with in cell assembly a dichotomy must be maintained between pouch cells, cylindrical cells and prismatic cells. Irrespective of the cell type, any Lithium-Ion Battery consisted of two electrodes and a separator- which separates the electrodes from each other. The ion conductive electrolyte fills the pores and remaining space of the battery. ● Technological Development: Recent technological developments will not decrease the material and manufacturing costs of the battery, but also improve the performance and characteristics of the battery. ● Product Innovations: ○ NMC 811( high nickel batteries). ○ Silicon graphite anodes. ○ Carrier materials and electrolytes. ■ Metal meshes. ■ Solid electrolytes. 5 ○ Fourth generation technology. ■ Large format cells. ■ Lithium metal anodes. ● Process Innovations: ○ Electrode manufacturing. ■ Extrusion. ■ Laser drying. ○ Cell assembly ■ Laser cutting ■ Coating of the separator. ○ Cell finishing. ■ Integrated product carrier. ■ Energy recovery. ● Electrode Manufacturing​: ○ Mixing: With the help of a rotating tool a minimum of two different raw materials are combined to make a mixture called "slurry". The material requirements of slurry include: ● Active materials. ● Conductive additives. ● Solvents ● Binders A difference is maintained between mixing( dry mixing) and dispersing ( wet mixing). It is encouraged to perform the process under vacuum conditions as to avoid contamination by gasses. The order of mixing and dispersing sequences is dependent on the electrode design. 6 Figure 3(a) ● Coating: The aluminum/copper foil used to make the electrodes is layered with the slurry using a slot die. Normally the top and bottom of the foil are layered separately, the top is layered first and sent for drying process. After the first drying process the foil returns for the bottom side of the foil to be layered​. Figure 3(b) 7 ● Drying: After the coating is applied the foil is moved for the drying process. The solvent present in slurry is removed from the now coated material by a heat supply. The highly flammable solvent used in the cathode mixing process is recovered. Figure 3(c) Roller system are being employed to move the foil with in the heating chambers. The dryer is divided into the chambers with different temperatures. ● Chamber 1 = 60°C ● Chamber 2 =160°C ● Chamber 3 = 160°C ● Chamber 4 = 80°C After passing through the dryer, the temperature of the foil is cooled to room temperature. ● Calendering: In the calendering process the copper or aluminum foil coated on both sides is compressed by a pair of rollers. The electrode foil is first discharged from any static current and cleaned via brushes. The foil is then compressed from the top. A force of 2500 N/mm is applied by the rollers. 8 Figure 3(d) ● Slitting: Slitting is a cutting process in which the calendered rolls( mother) are divided into smaller electrode coils ( daughter rolls). Normally, rolling knives are employed for the process. Figure 3(e) ● Vacuum Drying: The coated daughter rolls are stored in a vacuum oven. This process is used to remove any moisture or solvent present on the coils using evaporation process at low temperature and low pressure. 9 Figure 3(f) ● Cell Assembly ( Pouch Cells): ○ Separation: The separation of the cathode, anode and separator sheet from the daughter rolls are important for the production of the pouch cells. The cutting process is generally done by shear cut( punching tool) in a running process. Figure 4(a) ● Stacking: In this process the sheets of the cathode, anode and separator are stacked or placed in the following order; Anode, separator, cathode, separator. Generally, the Z-folding method is used. 10 Figure 4(b) ● Packaging: In this process the stacked coils are packed into pouch cells, one side of the cell is sealed air tight, the other is not sealed yet to insert the electrolyte. The current coils ( electrodes) are first attached to the cell tabs using laser welding process. Figure 4(c) ● Electrolyte Filling: The electrolyte is inserted into the packaged cell under vacuum ( filling) using a high precision dosing needle. Furthermore, with the application of a pressure profile results in the starting of the capillary effect in the cell( wetting). Finally, the cell is sealed under vacuum. 11 Figure 4(d) ● Cell Assembly ( Prismatic Cells, Cylindrical Cells): ○ Winding: The electrode coils and separator foils are wound together using a winding mendrel( Prismatic Cells) and a center pin ( Cylindrical Cells). The order of the foils is similar to the stacking process. The wounded product is called "jelly roll". Figure 5(a) ● Packaging: The jelly roll is placed in a hard metal casing. In the rismatic cells the jelly rolls edges are compacted, and attached to the contact terminals of the battery using laser welding. An insulator foil is wrapped around the jelly roll during insertion in the metal. The metal is afterwards, sealed using laser welding. 12 Figure 5(b) For Cylindrical Cells the jelly roll is inserted after a bottom insulator is added in the cylindrical shaped metal casing. The anode is welded with the bottom of the container where as, the cathode to the lid. An insulation ring is also added between the lid and jelly roll. ● Electrolyte Filling: The electrolyte is added after the jelly roll is fixed k. The container.The electrolyte is inserted into the packaged cell under vacuum ( filling) using a high precision dosing needle. Furthermore, with the application of a pressure profile results in the starting of the capillary effect in the cell( wetting). Finally, the cell is sealed under vacuum. Figure 5(c) 13 ● Cell Finishing: ○ Formation: It is the process in which the battery is charged and discharged for the first time. The cells are put in special good carriers, information racks and contacted by spring loaded contact pins. The cells are than charged and discharged in accordance with precise current and voltage curves. Figure 6(a) The Lithium Ion is introduced in crystalized form with graphite on the anode side. As a result, the Solid Electrolyte Interface( SEI) is formed, which produces an interface layer for the electrode and electrolyte. ● Degassing( Pouch Cells): During the first charge of the pouch cells, gas is produced. To avoid contamination the gasses are sucked out in a vacuum chamber. The cells are than sealed under vacuum. Figure 6(b) 14 ● Aging: It is the final process for the cell production and is a method to determine the quality of the product. During aging, the cells are regularly put under observation by noting the Open Circuit Voltage (OCV) for up to three weeks. A difference is maintained between High Temperature (HT) aging and Normal Temperature (NT) aging. The cells undergo HT aging first, followed by NT aging. The batteries are stored in aging shelves. Figure 6(c) if there is no significant change in the cell properties the entire time period, the cell is fully functional and quality assured. 15 Production Environment: Figure 7 16 Factory Production Layout: Figure 8 Quality Management: ● Quality Assurance and Control: Before the product can be shipped, the battery undergoes numerous years to make sure the no detrimental affects can be caused by the battery. This process is made compulsory to filter out any defected batteries with in the batch and that the product is consumer friendly. The battery undergoes different test and testing standards, such as electrical safety, temperature, shock and vibration tests, various environmental condition, such as humidity, temperature, pressure. The charging and discharging is performed using various current flows. The battery is later on checked in the over all application system, making sure it meets all the prerequisites. 17 Temperature and the rate of charging/ discharging is a known stress factor for the battery. The material used for production process must also meet the FMECA requirements. In the manufacturing process, the materials are subjected to Acceptance Quality Limit ( AQL) tests which test the materials to a minimum specifications. Figure 9(a) During the production process, the product goes through Quality Control(QC) inspection after each production step. Random tests are also performed alongside the QC testing. Before the batteries can be transported for consumer use they undergo one final test, the battery must undergo the UN38.5 testing method for transport. Once the test is passed the batteries are marked accordingly. Without this test the batteries can only be transported with a permit. Figure 9(b) 18 ● Future Prospects: Researchers ahve developed a new tool to detect flaws in lithium ion batteries during the manufacturing process. This test will pave an easier way to reducing defects and abnormalities in the thickness of the electrodes, that affect the battery life and reliability. "Lithium ions travel from the anode to cathode, while the battery is being charged and in the reverse direction when discharging energy. The material expands an lithium ion s travel into it, and this expansion and contraction causes mechanical stresses, that can eventually damage the battery and reduce it's lifetime". Said Douglas Adams, Kenningar Professor of Mechanical Engineering and Director of the Purdue Center for Systems Integrity. Figure 9(c) The Purdue researchers have developed a tool that employs a flash bulb like heat source and a thermal camera to read how heat travels with in the electrode. The "flash thermography measurement" takes less than a second and tevelas the differences in thickness and composition. 19 Costs and Economics: ● Cost Analysis: The prices of lithium ion batteries have dropped by ~80-85 percent in the last decade. It is also believed that the batteries will drop as low as $60/KWh by 2030, all of which was and will become possible due to technological advancements and economical scales. The prices have dropped faster than predicted and this trend seems to be predominant in the next decade as well. Figure 10(a) The raw material cost, includes the cost of electrodes, electrolyte, separator, cell assembly and other materials. The prices of lithium only amounts to about 16% of the average battery price. The price of separator, electrolyte and assembly bcontributes to only 50% of the average cost. Figure 10(b) 20 Lithium Ion Batteries manufacturers like; LG Chem, Tesla, Lithium Work B.V. and BYD are continuously improving production capacity by setting up Giga factories. For example, BYD of China has invested $1.49 billion in a 20 GWh giga factory in China. ● Future Prospects: Future cost reductions can be attained through greater understanding of the structure of electrodes. Researchbis being focused on the molecular mechanisms and improve design of electrodes m thicker electrodes will improve energy density at lower costs. 21 Conclusion: There Is no doubt that the manufacturing process for the lithium ion battery is quite numerous, from electrode manufacturing to cell assembly to the cell finishing process followed by several safety and quality tests. However, the final product obtained through this thorough method is the fossil free future we need. Nowadays, every technological innovation is dependent on the batteries, which in itself shows the importance of the industry. Not only is the product an eco-friendly power source, but also an affordable one as well. 22 References: 1. Zhao Liu (2020) The History of the Lithium-Ion Battery, Available at: https://www.thermofisher.com/blog/microscopy/the-history-of-the-lithium-ion-battery/#:~ :text=The%20History%20of%20the%20Lithium-Ion%20Battery,-By%20Zhao%20Liu&t ext=In%20the%20late%201970s%2C%20a,electric%20vehicles%20and%20mobile%20 phones​.​ (Accessed: 28th December 2020). 2. RELiON Batteries (2020) The Seven Top Uses For Rechargeable Lithium-Ion Batteries, Available at: https://relionbattery.com/blog/the-seven-top-uses-for-rechargeable-lithium-ion-batteries (Accessed: 28th December 2020). 3. Heiner Hans Heimes, Achim Kampker, Christoph Lienmann, Marc Locke, Christian Offermanns (December 2018) LITHIUM-ION BATTERY CELL PRODUCTION PROCESS, 3rd edn., Frankfurt am Main: VDMA Battery Production 4. Ulrich Sonndag (February 2017) 'Quality Assurance: Risk Mitigation for Lithium-Ion Battery Packs', Medical Design Briefs Magazine, 1(1), pp. [Online]. Available at: https://www.medicaldesignbriefs.com/component/content/article/mdb/issue-archive/3405 2​ (Accessed: 28th December 2020). 5. Nathan Sharp, Peter O'Regan, Anand David, Mark Suchomel (2013) Lithium-ion Battery Electrode Inspection Using Flash Thermography,, Lombard: Purdue University 6. Jegan Venkatasamy (2020) Lithium-Ion Batteries - Price Trend and Cost Structure, Available at: https://www.beroeinc.com/article/lithium-ion-batteries-price-trend-cost-structure/ (Accessed: 28th December 2020). 7. Clause Daniel (2015) 'Lithium Ion Batteries and Their Manufacturing Challenges', Spring Bridge: From the Frontiers of Engineering and Beyond, 45(1), pp. [Online]. Available at: https://www.nae.edu/134258/Lithium-Ion-Batteries-and-Their-Manufacturing-Challenges #:~:text=Lithium%20ion%20batteries%20are%20manufactured,create%20a%20porous %20electrode%20coating​. (Accessed: 28th December 2020). 23