LG Energy applies new degassing process to US battery factory 

LG Energy Solution has applied a new degassing process to the first battery factory of Ultium Cells, its joint venture with General Motors, at Lordstown, Ohio, TheElec has learned.

The degassing process is a back-end process done before packaging during pouch battery production. 

Previously, cells were laid down horizontally during the process. The new process has the cells stand vertically for the degassing.

The equipment used for the new way are 40% smaller than their predecessor. This new process has decreased defect rate substantially, sources said.

The process is not needed for cylinder and prismatic batteries that have empty spaces where gas can settle in. Pouch batteries don’t have this space.

Pouch battery cells goes through notching, which creates the positive and negative tabs, then stacking, and then tab welding. Then there is the vacuum sealing process __ an air pocket is added to inject electrolyte and collect gas. Once the degassing process is done with, this air pocket is cut and removed. Where the air pocket was cut out from is folded (edge folding) to seal it. Batteries are than heat pressed, then packaged.

Because cells were laid down horizontally, when the air pocket was cut out, electrolyte will also inevitably leak. This method has been prevalent in Japanese battery equipment makers such as Canon. 

Having the cell placed vertically allows the pocket to be removed without electrolyte leaking.  

The equipment for the process was also previously around 45 meters long. This has now been reduced to around mid-20 meters. 

Shorter equipment means shorter production line, which increases its productivity.

LG Energy Solution is planning to apply the new degassing process to all its battery factories, including those in Poland and China. The move will save the company is cost, the sources said.

Meanwhile, LG is planning to secure a production capacity of up to 145GWh in the US from Ultium Cells and its own factories there.