South Korean battery makers LG Chem and SK Innovation are sparring again over an ongoing case regarding a violation of an electric battery patent.

On Sunday, the companies each released statements on the status of their EV battery patent case being investigated by the US International Trade Commission.

The case was filed by SK Innovation last September, following LG Chem’s filing of a trade secret misappropriation case against the company in April 2019.

It was reported that LG Chem filed a motion with the ITC last month, seeking the issuance of an order sanctioning SK Innovation for “destruction of highly relevant evidence” after the litigation began.

LG Chem said in the motion that SK Innovation destroyed documents related to the EV battery patent with the intention of destroying relevant information in their possession.

LG also claimed SK Innovation employees were repeatedly instructed to “delete all materials related to the rival company ... and delete this email after completing this directive.”

On Friday, SK Innovation dismissed LG Chem‘s accusations, saying it “has no reason whatsoever to delete the documents and it did not delete them.”

SK also claimed the company solely developed the pouch-type 994 patent being discussed in the latest tit-for-tat, unlike LG’s assertion.

LG said SK could develop the 994 patent based on LG’s A7 battery cell that was launched in 2013 prior to the 994 patent being registered in 2015. The A7 battery cells were used in the Chrysler Pacifica minivan in 2013.

“Once a patent is issued, the technology is open to the public,” said SK in the Sunday statement. “They would have known if the 994 patent violated its A7 technology by the time we filed the complaint last year, which they didn’t even recognize.”

They found some similarities between the two patents two months after the complaint was filed, using the A7 technology in particular to defend itself in the patent case, SK said.

However, LG clarified that the company didn’t apply for a patent for the A7 cell technology because it didn’t include high-level technological features that had to be protected by patent application.

“SK should give an answer to why it possessed LG’s information regarding the technology, and why it attempted to destroy the documents,” LG said.

LG Chem and SK Innovation have been in conflict over EV battery-related trade secrets since last year, filing multiple lawsuits in the US and Korea.

In February, the US ITC made a preliminary ruling in favor of LG Chem’s argument that SK Innovation had misappropriated and used its EV battery trade secrets.

The US trade panel is set to make its final ruling on the case in October.

By Song Su-hyun (song@heraldcorp.com)