Takeaways: Five smart ways to improve EV battery production

1. For cell manufacturing, precisely align key components to improve overall performance and lifetime of the battery.

Focusing on the precise glue dispensing step is where manufacturers can efficiently meet safety goals (preventing battery shorts), while imparting build quality into the battery and saving on scrap.

Fluid dispensing expertise from Nordson EFD recommends the correct solution for the exact, repeatable application of adhesive to facilitate accuracy in battery layer alignment within the cell.

For this task, the Nordson EFD PICO Pµlse XP jetting system offers many advantages for battery manufacturing because it enables manufacturers to accurately, repeatedly, and precisely dispense fluids.

Offering micron (µm) level stroke adjustment (a human hair is approximately 70 microns), the solution can repeatedly dispense fluids over long periods of time, regardless of environmental factors.

In addition, the system can apply micro-deposits as small as 0.5 nL at speeds up to 1000Hz (deposits per second) continuously.

2. For cell manufacturing, ensure precise electrolyte filling for the overall performance and stability of the cell.

Precise electrolyte filling is important for battery manufacturers because using just enough electrolyte to wet the components contributes to optimal cell performance. Electrolytes are known to be aggressive fluids, so careful handling of the material is essential for satisfactory results.

Smart manufacturers pay particular attention to their choice of valves for this process, as they must be able to stand up to the aggressive nature of the electrolyte without requiring frequent valve change outs.

For this application, Nordson recommends that manufacturers use a 702 series mini-diaphragm valve. This valve is particularly well suited to filling electrolyte chambers because it provides a drip-free dispensing. The mini-diaphragm valves feature a distinctive design that eliminates trapped air bubbles and offers quick, clean cutoff.

The 702 mini-diaphragm valves offer a tamper-resist stroke adjustment, consistent shot-to-shot performance, and faster throughput. In addition, the 702 Series valves enable users to mount more valves per fixture plate and dispense fluids in tighter spaces, allowing greater throughput and productivity.

3. For module and pack assembly, use a controlled and automated thermal interface material (TIM) dispensing method to prevent thermal runaway, which is critical for overall battery pack safety.

Thermal runaway is a chain reaction within a battery cell that involves a rapid rise in the temperature of the battery. It occurs when the temperature inside a battery reaches a point that causes a chemical reaction to occur inside the battery. This chemical reaction produces more heat, driving the temperature higher — causing further chemical reactions that create more heat.

Causes for thermal runaway include:

• An internal short circuit caused by physical damage to the battery or poor battery maintenance.

• Overcharging a battery beyond its safe max voltage (to extend the distance an electric car will run, for example), which can permanently damage the battery and lead to thermal runaway.

• Rapid charging because rapid charging can lead to excessive currents.

• Finally, temperatures outside of the safe region on either the low or high side degrades a battery’s performance. This leads to irreversible damage to the battery and possible triggering of the reaction.

One method to prevent thermal runaways is the use of thermal interface materials (TIM), since the material absorbs the heat from the overheated batteries. To achieve this, design engineers need to calculate and precisely apply the right amount of the selected TIM chemistry at the exact locations in the battery module and the battery pack. This is an operation where the use of leading fluid dispensing technology can prevent thermal runaway.

Nordson EFD technology helps automate TIM dispensing using the fluid dispensing capabilities of 797PCP-2K progressive cavity pumps. The quality assurance this manufacturing technology imparts is precise dispensing of the right amount of fluid in a repeatable manner.

4. For module and pack assembly, reduce the cycle time and increase the repeatability and accuracy of the bonding operation of the battery cells to the battery tray to increase production yield and save valuable production time.

A non-contact dispensing solution like Nordson EFD’s PICO Pµlse jet valve can be the difference between repeatable battery cells to battery tray bonding, and struggling with frustrating production errors.

Using the PICO Pµlse solution’s exchangeable, modular jet valve technology, manufacturers can apply precise, repeatable micro-deposits at 1000Hz continuously, with bursts up to 1500Hz.

Manufacturers can also reduce cycle times, too. Difficult to reach dispensing areas like the complex honeycomb structures found in many battery modules can present a challenge, but jet valves paired with the right automated dispensing system provide the flexibility to apply fluids and adhesives onto nearly any battery tray geometry.

5. In all areas of fabrication, future proof by staying flexible in production methods by adapting to new battery chemistries and technologies.

Currently, Li-ion batteries are the prevailing power technology for EV vehicles. But the dynamic nature of market forces and disruptive technology is such that savvy battery builders are keeping their eye on emerging battery chemistries. These include solid state battery and fuel cell designs.

Nordson EFD fluid dispensing solutions are used to manufacture various types of cell geometry. In addition, Nordson EFD and the Nordson family of companies are actively engaged in researching the next generation of battery innovations like different cell chemistries and technologies.

By focusing on above five areas of production process, manufacturers will manufacture high performance batteries with a long-life cycle while maximizing production yield, concluded Muge Deniz Meiller.