Electra Battery Materials Corporation Establishes At-The-Market Offering

Electra Battery Materials Corporation has established an At the Market Offering (ATM) with H.C. Wainwright & Co., LLC, allowing the company to offer and sell up to US$5,500,000 in common shares. The ATM is being conducted in the United States under a registration statement declared effective by the SEC on December 11, 2025. Sales will occur at prevailing market prices on the Nasdaq Stock Market LLC, with a 3.0% cash commission paid to the underwriter. The net proceeds are intended for use as outlined in the prospectus. Electra Battery Materials focuses on advancing North America's critical minerals supply chain for lithium-ion batteries, including operating North America's only cobalt sulfate refinery and advancing black mass recycling opportunities. This filing is an Exhibit 99.1 to a Form 6-K report dated December 22, 2025.