# Sujeet Kumar

> Sujeet Kumar is the co-founder and CEO of Ionblox, a Fremont, California battery company building pre-lithiated silicon-anode lithium-ion cells for electric vehicles and electric aviation. A materials scientist with a Ph.D. from the University of Rochester and more than 60 patents to his name, he previously served as CTO of Envia Systems, where his team developed one of the first 400 Wh/kg lithium-ion cells with a silicon anode. Ionblox, formerly Zenlabs Energy, has raised roughly $32 million in Series B funding from backers including Lilium, Applied Ventures, Temasek and Catalus Capital, and markets cells that promise higher energy density, up to five times more power, and 10-minute fast charging.

- **Role:** Co-founder, CEO & Board Member at Ionblox
- **Organizations:** Ionblox, Zenlabs Energy, Envia Systems, Nanoexa, Greatbatch, Nanogram Devices Corporation
- **From:** India
- **Nationality:** Indian-American
- **Education:** B.Tech, Indian Institute of Technology (BHU), Varanasi, Ph.D. in Materials Science, University of Rochester
- **Known for:** Co-founded and leads Ionblox, a battery company commercializing pre-lithiated silicon-anode lithium-ion cells, Inventor on more than 60 patents, Won an R&D 100 award in 2009 for high-energy lithium-ion battery work

## Career timeline

- **2000s** — Principal scientist at Nanogram Devices Corporation and senior scientist at Greatbatch, developing cathode materials
- **2000s** — Director of Technology at Nanoexa
- **2009** — Won an R&D 100 award for work on high-energy lithium-ion batteries
- **2010s** — Served as CTO of Envia Systems, where his team developed one of the first 400 Wh/kg lithium-ion cells with a silicon anode
- **2017** — Co-founded Zenlabs Energy (later renamed Ionblox) as founder and CEO
- **2022** — Ionblox announced a $24M Series B round with Lilium, Applied Ventures and Catalus Capital
- **2023** — Ionblox closed Series B at $32M, adding Temasek to its investor base

## Achievements

- Co-founded and leads Ionblox, a battery company commercializing pre-lithiated silicon-anode lithium-ion cells
- Inventor on more than 60 patents
- Won an R&D 100 award in 2009 for high-energy lithium-ion battery work
- As CTO of Envia Systems, led a team that developed one of the first 400 Wh/kg lithium-ion cells with a silicon anode
- Raised approximately $32 million in Series B funding from Lilium, Applied Ventures, Temasek and Catalus Capital
- Secured a licensing partnership with eVTOL manufacturer Lilium for cell technology in regional air mobility

## Latest updates

- **2023-02** — Ionblox closed its Series B at $32 million with participation from Lilium, Applied Ventures, Temasek and Catalus Capital.
- **2024-12** — Ionblox's eVTOL partner Lilium filed for insolvency, with its German assets slated for acquisition by the Mobile Uplift consortium.

## Links

- Website: https://ionblox.com
- LinkedIn: https://www.linkedin.com/in/sujeet-kumar-3821a41
- Twitter/X: https://twitter.com/ionblox_

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Profile page: https://yespress.io/sujeet-kumar
Published by YesPress — https://yespress.io
Last updated: 2026-07-24