Challenges during lithium-ion cell manufacturing setup – Part 4

June 13, 2023 Lithium-ion batteries 7 min read

Plant Setup Planning

Rahul Bollini is writing a series of articles explaining the challenges faced during Lithium-ion cell manufacturing plant setup, which should be relevant to any company entering this field. This article (part 4 of the series) explains the challenges faced during the Lithium-ion cell manufacturing plant setup.

When companies venture into Lithium-ion cell production, they typically establish a laboratory setup to familiarize their team with the details and complexities of the manufacturing process. This laboratory set up also serves to conduct a more thorough analysis of the crucial raw materials involved.

The first step towards understanding the characteristics of critical raw materials such as Cathode is to make a half cell, which is made using a Lithium metal anode. Characteristics such as specific capacity during discharge are studied at a low C rate (0.1C or 0.2C rate). Along with it, the first discharge efficiency and other performance-related parameters are studied to understand the electrochemical nature of the material. The particle size of the Cathode is also studied at a very high magnification scale to understand the physical nature of the material. Similarly, each raw material needs to be studied and finalised before incorporating for regular production. Typically, companies finalize two or three vendors for each type of raw material to ensure a consistent supply and competitive pricing.

The laboratory set-up is scaled up to a pilot (typically in MWh capacity) to test the cells at a mass scale and provide the cells to the potential clients for qualification. The successful qualification provides an opportunity to take orders on a larger scale, ultimately leading to Giga-scale production.

When planning a plant setup, there are multiple concurrent tasks that need to be planned and carried out. Here are the specifics of these tasks:

Equipment Planning

Planning for a Lithium-ion plant setup is a meticulous process that requires intensive discussions with the third-party company responsible for sourcing and installing all equipment. Such a company is called a system integrator. Sometimes the scope of the plant equipment is split, and sourcing is done directly from the equipment manufacturer.

Opting for the second approach may result in cost savings, but it can pose challenges during the plant’s commissioning process. In case production output falls short of expectations, equipment suppliers may engage in a blame game. Any new company is advised to work with a system integrator who can take complete responsibility for the plant’s functioning and can guarantee the desired output.

Either way, the production process and the cell design are to be shared with the equipment company to help them understand the type of cell(s) to be manufactured. If you intend to produce multiple types of cells in the same production line, it is recommended to opt for a less automated approach to allow flexibility. Fine-tuning the production plant takes up a few months usually, and more details will be discussed about it in part 5 of this series, where I’ll talk about the challenges faced during the process optimisation at a Giga-scale plant.

Infrastructure Planning

The waste discharge in Lithium-ion cell manufacturing is minimal due to the solvent recovery process during electrode manufacturing (the cathode uses NMP solvent, and the anode uses deionized water). Still, it is difficult to get clearance to establish a Lithium-ion cell manufacturing facility in no polluting or low-polluting zones. Authorities tend to allow the setup in high to very high polluting areas only. Land acquired in these zones is generally far away from the city and poses a challenge for a skilled workforce. More details about challenges for a skilled workforce are to be discussed in part 5 of this series.

Generally, Giga factories are planned in multi-storeyed buildings to enable better monitoring so that different teams involved in various processes can work well together. Typically, a two-storeyed building is preferred. In this case, the bottom floor handles the incoming raw materials and feeds them to the mixer. The mixer output is taken to coating, which is followed by a long drying process, usually starting from 40m in length.

Dry room infrastructure planning is also crucial since it needs to be up and running most of the time, and any downtime can temporarily stop production. The relative humidity and dewpoint temperature can vary for each process area and need to be selected accordingly; it will be less strict in the coating room but stricter in the electrolyte filling room. These parameters can also vary depending on the type of cathode being used. NMC handling conditions are stricter than LFP handling conditions. Dry room power consumption tends to be more when the conditions are stricter (lower relative humidity and lower dewpoint temperature). These parameters are also set based on the number of people working inside the dry room and based on the number of times the dry room door is opened in a given time.

Utility Planning

Lithium-ion cell manufacturing at a Giga scale needs a significant amount of power. One GWh/year plant capacity needs to have an approximate connected load of nearly 10MW, and it can vary depending on the level of automation. An uninterrupted power supply is a must for Lithium-ion cell manufacturing and dry room operations, and many MVA-sized diesel generators are needed to ensure that. Deionized water is actively used as a graphite-based anode solvent, and its requirement can be close to 1.5 Million litres for one GWh capacity.

Upcoming parts of this series:

Part – 5 (Process Optimisation and Skilled Man Power)
Part – 6 (Expansion and Diversification of Portfolio)
Part – 7 (Evolving to Newer Technologies)
Part – 8 (Backward Integration)

Rahul Bollini is an R&D expert in Lithium-ion cells with 8 years of experience. He founded Bollini Energy to assist in deep understanding of the characteristics of Lithium-ion cells to EV, BESS, BMS and battery data analytics companies across the globe. Rahul can be reached at +91-7204957389 and bollinienergy@gmail.com.