Amprius Technologies Announces CEO Transition

Key Terms

lithium-ion batteries technical

Rechargeable lithium-ion batteries are lightweight, high-energy storage cells that use lithium ions moving between electrodes to store and release electricity, like a refillable fuel tank for electronic devices and electric vehicles. Investors care because they power a wide range of products from phones to cars and grid systems, so improvements, costs, supply chain constraints, or safety issues can directly affect manufacturers’ profits, product demand, and capital expenditure plans.

silicon anode technical

A silicon anode is the negative electrode in a rechargeable lithium-ion battery that uses silicon instead of or alongside graphite to hold lithium ions. Because silicon can store many more ions per volume—like packing a suitcase far more tightly—it can enable higher battery capacity, faster charging or longer life, which matters to investors because it can lower costs, improve product competitiveness and affect demand across electric vehicles, electronics and energy storage markets.

silicon anode platform technical

A silicon anode platform is a battery technology that uses silicon in the negative electrode instead of traditional carbon to store more electrical charge; think of it as swapping a small sponge for one that soaks up much more water. It matters to investors because it can enable batteries with higher range, faster charging, or lower cost per mile, but also carries technical and manufacturing risks that affect product timelines, costs and competitive advantage.

electrolyte technical

Electrolytes are tiny charged particles dissolved in a liquid that allow electricity to flow—think of them like salt in soup that makes current move through the liquid. They matter to investors because they are core to battery performance, energy storage, and certain medical products; their composition and quality affect product efficiency, safety, regulatory approval, supply chains and production costs, all of which can influence a company’s financial prospects.

Amprius President Tom Stepien appointed Chief Executive Officer by Board of Directors, effective January 1, 2026

Dr. Kang Sun to retire at the end of 2025 and will continue serving on the Amprius Board while acting as an Executive Advisor, providing strategic guidance to the Company

FREMONT, Calif.--(BUSINESS WIRE)-- Amprius Technologies, Inc. (“Amprius” or the “Company”) (NYSE: AMPX), a leader in next-generation lithium-ion batteries with its Silicon Anode Platform, today announced that its Board of Directors (the “Board”) has appointed President Tom Stepien as its next Chief Executive Officer (“CEO”), effective January 1, 2026.

Amprius President Tom Stepien appointed chief executive officer by the Board of Directors, effective January 1, 2026.

Current Amprius CEO Dr. Kang Sun will be retiring at the end of 2025. Dr. Sun will continue to serve as a director on the Board and as an Executive Advisor, providing strategic guidance to the Company.

Dr. Sun founded Amprius in 2015 and has served as its CEO since. In that time, he has led the Company in pioneering and commercializing silicon-anode batteries that have achieved industry-leading energy density and performance milestones. Under his leadership, Amprius has become an innovator in advanced battery solutions for aerospace, electric mobility, and other high-performance applications, helping to shape the future direction of next-generation batteries.

“Leading Amprius Technologies has been one of the most rewarding experiences of my career,” said Dr. Kang Sun. “I am proud of what our team has accomplished in advancing silicon anode technology from the lab to commercial deployment. As I transition from the CEO position, I look forward to supporting Amprius in my ongoing roles and helping the Company continue to grow while delivering breakthrough solutions to our customers.”

Tom Stepien joined Amprius as President in May 2025 and has strengthened operations, expanded customer engagement, and advanced the Company’s growth strategy. Stepien brings over 35 years of leadership experience across customer-focused, innovation-driven technology companies. Prior to Amprius, Stepien served as CEO of South 8 Technologies, a provider of novel electrolyte for lithium-ion batteries; cofounded and led Primus Power, a long-duration stationary storage company; and was an Operating Partner at KCK Group, a private equity firm focused on industrial technologies. Earlier in his career, he held leadership roles at Applied Materials, the global semiconductor equipment leader.

“I am honored to step into the role of CEO and advance the industry-leading foundation that Kang and the team have built,” said Stepien. “Amprius’ silicon anode technology continues to set new standards for performance, and I look forward to leading the Company through its next phase of growth and innovation.”

“On behalf of the Board and the entire Amprius team, I want to thank Kang for his exceptional leadership and pioneering vision,” said Don Dixon, Chairman of the Board. “We are equally excited to welcome Tom as CEO. With his leadership experience and deep knowledge of the energy storage industry, Tom is well-positioned to drive Amprius’ continued success.”

For more information, please visit the Amprius investor relations website at ir.amprius.com.

About Amprius Technologies, Inc.

Amprius Technologies, Inc. is a leading manufacturer of high-energy and high-power lithium-ion batteries, producing the industry’s highest-known energy density cells. The Company’s commercially available SiCore® and SiMaxx™ batteries deliver up to 450 Wh/kg and 1,150 Wh/L, with third-party validation of 500Wh/kg and 1,300 Wh/L. The Company’s corporate headquarters is in Fremont, California, where it maintains an R&D lab and a MWh scale manufacturing facility for the fabrication of silicon anodes and cells. To serve customer demand, Amprius entered into several agreements to secure over 2.0 GWh of contract manufacturing capacity. For additional information, please visit amprius.com. Also, see the Company’s LinkedIn page.

Forward-Looking Statements

This press release includes “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, each as amended. Forward-looking statements may be identified by the use of words such as “estimate,” “plan,” “project,” “forecast,” “intend,” “expect,” “anticipate,” “believe,” “seek,” “will” or other similar expressions that predict or indicate future events or trends or that are not statements of historical matters. These forward-looking statements include, but are not limited to, statements regarding the performance of Amprius’ products, the growth of Amprius’ business, and the capacity of Amprius through its contract manufacturing network. These statements are based on various assumptions, whether or not identified in this press release, and on the current expectations of Amprius’ management and are not predictions of actual performance. Actual results could differ materially from these forward-looking statements as a result of certain risks and uncertainties. These forward-looking statements are subject to a number of risks and uncertainties, including Amprius’ liquidity position; risks related to the rollout of Amprius’ business and the timing of expected business milestones; Amprius’ ability to commercially produce high performing batteries; the effects of competition on Amprius’ business; supply shortages in the materials necessary for the production of Amprius’ products; and changes in domestic and foreign business, market, financial, political and legal conditions. More information on these risks and uncertainties that may impact the operations and projections discussed herein can be found in the documents we filed from time to time with the Securities and Exchange Commission (the “SEC”), all of which are available on the SEC’s website at www.sec.gov. There may be additional risks that Amprius does not presently know or that Amprius currently believes are immaterial that could also cause actual results to differ from those contained in the forward-looking statements. In addition, forward-looking statements reflect Amprius’ expectations, plans or forecasts of future events and views as of the date of this press release. These forward-looking statements should not be relied upon as representing Amprius’ assessments as of any date subsequent to the date of this press release. Accordingly, undue reliance should not be placed upon the forward-looking statements. Except as required by law, Amprius specifically disclaims any obligation to update any forward-looking statements.

View source version on businesswire.com: https://www.businesswire.com/news/home/20251222049691/en/

Investors

Tom Colton, Greg Bradbury

Gateway Group, Inc.

949-574-3860

IR@amprius.com

Media

Zach Kadletz, Brenlyn Motlagh

Gateway Group, Inc.

949-574-3860

Amprius@Gateway-grp.com

Source: Amprius Technologies, Inc.