Full-Time
Mechanical Engineer
Updated on 8/23/2026
Adden Energy
11-50 employees
Develops solid-state lithium-metal EV batteries
No salary listed
H1B Sponsorship Available
Waltham, MA, USA
In Person
Bachelor's, Master's
 Mechanical Engineering (1) |
|---|
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- Strong hands-on experience with equipment maintenance and repair.
- A Bachelor’s or Master’s degree in mechanical engineering, chemical engineering, or a related field.
- At least 2 years of experience in a mechanical design role in a lithium-ion battery industrial environment.
- Hands-on experience with roll-to-roll coater installation, maintenance, and operation.
- Experience with vendor qualification and customer interactions.
- Ability to work safely and in compliance with all regulations and quality systems.
- Conduct regular maintenance and repair of lab equipment.
- Design, modify, and optimize mechanical fixtures for solid-state batteries.
- Design and develop pilot-scale electrode coating tools based on the company’s cell technology.
- Design tools and analyze concepts using computer-aided design software such as SolidWorks.
- Work with external suppliers to customize equipment based on manufacturing processes.
- Set up and validate pilot-scale slurry mixers, electrode coaters, and other cell fabrication equipment.
- Maintain, modify, and optimize equipment according to vendor guidelines.
- Experience with ceramic solid electrolytes.
Adden Energy develops advanced solid-state batteries for electric vehicles. Its core product is a dynamically-stable lithium-metal battery designed to replace traditional lithium-ion cells. The battery can potentially charge in as little as three minutes and endure over 10,000 cycles in laboratory tests, with ongoing efforts to improve low-temperature performance. The company operates with a business-to-business model, targeting automotive OEMs and running a pilot production line to manufacture sample cells for potential customers. Backed by substantial funding and rooted in Harvard University, Adden Energy aims to bring a commercially viable solid-state battery to market that enables faster charging, longer life, and easier adoption of EVs by a wider range of consumers.
Company Size
11-50
Company Stage
Series A
Total Funding
$25.4M
Headquarters
Waltham, Massachusetts
Founded
2021
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Simplify's Take
What believers are saying
- Adden’s July 18, 2026 website update keeps the company visibly active and recruiting.
- Automaker purchase orders from February 2025 create near-term validation demand for the pilot line.
- Series A backing from At One Ventures and Primavera funded roll-to-roll scale-up.
What critics are saying
- No public Series B exists, so 2026 scale-up depends on OEM orders and fresh capital.
- Validation cells do not equal volume contracts; OEMs can walk after sample testing.
- A failed pilot-line scale-up kills the Harvard spinout before SOP.
What makes Adden Energy unique
- Harvard’s dynamic-stability chemistry powers Adden’s lithium-metal cells with three-minute charging and long cycle life.
- The February 2025 pilot line uses standard lithium-ion equipment, lowering manufacturing transition risk.
- Adden already ships validation cells to automakers and industrial users, a rare pre-production signal.
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Benefits
Health Insurance
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Growth & Insights and Company News
6 month growth
↓ -4%1 year growth
↑ 0%2 year growth
↑ 0%Adden Energy has officially launched a pilot production line to manufacture its dynamic-stability lithium metal solid-state batteries, aiming to advance battery technology with improved energy density, faster charging, and enhanced safety.
Adden Energy, a solid-state battery startup that spun out of Harvard, raised $15 million in Series A funding led by At One Ventures.
Electric Vehicle (EV) adoption is one of the most meaningful steps an individual can take to combat climate change. Yet, current battery performance i
The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.The reader should not assume that the information is accurate and complete.
WALTHAM, Mass.--(BUSINESS WIRE)--Adden Energy, a leading developer of solid-state batteries, announces that its record-breaking lithium metal batteries can now maintain extreme-fast-charging (EFC) of less than 10 minutes at room temperature. No other lithium metal batteries can reliably charge this fast even at elevated temperatures, nevertheless at the room temperature required for electric vehicles (EVs). Such EFC solves one of the biggest bottlenecks facing widespread adoption of EVs. “The slow charge rates of Li-ion batteries have made EVs inaccessible to too many,” said Will Fitzhugh, CEO of Adden Energy. “Over a third of American’s lack dedicated at-home parking, so the current paradigm of at-home charging just doesn’t work. Our technology makes EV charging as fast as gas, so you can recharge using public infrastructure on your lunch break or the way home from work.”