SK Innovation has applied Gen 3 Z-stacking equipment to its battery production lines, TheElec has learned.
Stacking equipment is used to attache the separator between the cathode and anode. It is the next step to notching in battery production.
The new Gen 3 Z-stacking was first applied to SK Innovation’s factory in Seosan, South Korea, its so-called “Mother Fab”. Its application will likely be expanded the company’s facilities in China, Hungary and the US.
Its Gen 3 Z-stacking equipment is 30ppm fast, which is 2.3 times faster than the Gen 1 equipment applied in the early 2010s.
Previous equipment had limitations on handling battery materials that were increasingly becoming longer, which hampered productivity.
Samsung SDI also uses Z-stacking in its battery production. LG Energy Solution, meanwhile, uses lamination and stacking. Unlike Z-stacking, where cathode and anode are stacked inside a magazine, LG Energy Solution attaches the electrode on to the separator.
An automobile customer to SK Innovation had previously complained that the Z-stacking method used by the company was lacking in productivity to those of LG Energy Solution’s lamination and stacking, a person involved with SK Innovation’s stacking process said.
SK Innovation succeeded in develop Gen 3 Z-stacking back in 2018 and is currently researching ways to further expand the battery cell width to increase energy density, they said.
SK Innovation claims the Z-stacking method can solve the problem of not having the anode and separator inside the cell. Despite the 30ppm speed, the cells are also aligned well, causing no shorts, the firm also claims.
The company is also looking to automate its production line. Currently, notching and stacking processes are done separately. The company is looking to combine them through an in-line equipment.
SK Innovation is planning to place orders for its third factory in Hungary in August. The newer equipment may be applied here first for factories outside of South Korea.