Law360: Celgard Can't Salvage Battery Patent Claims At Fed. Circ.


Fish Principals Kevin Wheeler, Michael McKeon, and Tim Riffe represented LG Chem in a longstanding patent dispute with Celgard LLC. The case was reported by Law360 in the December 2016 article “Celgard Can’t Salvage Battery Patent Claims At Fed. Circ.”.

The full article is available to Law360 subscribers. A summary of the case is also provided below.

The US Court of Appeals for the Federal Circuit issued a Rule 36 judgment, affirming the Patent Trial and Appeal Board’s decision to invalidate several claims in a Celgard LLC patent covering lithium battery technology, which had been asserted in district court against LG Chem Ltd.

The appeals court affirmed PTAB’s October 2015 decision that LG Chem had demonstrated numerous claims in the patent were made evident by previous inventions and were therefore invalid.

Celgard produces lithium­ion battery parts for a variety of electronics, like computers, phones and electric vehicles. The subject of the patent dispute was a battery separator – a piece that allows the batteries to function but prevents the electrodes from coming in contact with one another.

Celgard sued LG Chem in 2014, alleging infringement of the patent. A district court judge granted a preliminary injunction, preventing LG Chem from supplying Apple Inc. and other companies with batteries that used the technology in dispute. The case quickly moved to the Federal Circuit, following the preliminary injunction order.

A year later, in August 2015, the appeals court reversed the preliminary injunction. In the meantime, with the assistance of Fish & Richardson, LG Chem filed a petition with PTAB seeking inter partes review of the patent. The petition contended that various claims were invalid. LG Chem was vindicated in a final written decision by the board, ruling that certain claims would have been obvious in light of two Japanese patent applications.