C. Ionel Stefan
About C. Ionel Stefan
Dr. C. Ionel Stefan is Chief Technology Officer (CTO) of Amprius Technologies, Inc. (AMPX) since September 2022, after serving as Legacy Amprius’ CTO since August 2015. He is 52 years old as of March 31, 2025, and is a recognized expert in electrochemistry who leads Amprius’ R&D to advance lithium-ion cell performance. His background includes a Ph.D. in Chemistry (Case Western Reserve University) and M.S./B.S. in Electrochemistry and Analytical Chemistry (Babes-Bolyai University), and prior electrochemistry roles at Nanosys Inc.
Past Roles
| Organization | Role | Years | Strategic Impact |
|---|---|---|---|
| Amprius Holdings | Battery science and development roles of increasing responsibility | 2009–2015 | Built foundational battery science capabilities leading to CTO role |
| Legacy Amprius | Chief Technology Officer | Aug 2015–Sep 2022 | Led R&D to advance lithium-ion cell performance |
| Amprius Technologies, Inc. | Chief Technology Officer | Sep 2022–present | Leads scientific R&D for high-performance lithium-ion cells |
| Nanosys Inc. | Scientist Electrochemist | Pre-2009 (prior to joining Amprius Holdings) | Electrochemistry experience relevant to advanced battery materials |
External Roles
| Organization | Role | Years | Notes |
|---|---|---|---|
| Not disclosed in proxy biographies | — | — | No external public company directorships mentioned in the executive biography sections |
Fixed Compensation
Base salary and target bonus
| Year | Base Salary (USD) | Target Bonus (% of Base) |
|---|---|---|
| 2022 | $250,000 | 30% |
| 2023 | $364,000 | 60% |
Actual annual bonus paid
| Year | Bonus Paid (USD) | Payment Timing |
|---|---|---|
| 2022 | $150,075 | On or before January 31, 2023 |
Performance Compensation
| Plan / Metric | Weighting | Target | Actual | Payout | Vesting |
|---|---|---|---|---|---|
| Annual Bonus (2022 EICP) | Not disclosed | 30% of base salary | Determined per Board/Comp Committee methodology; paid $150,075 | Paid on or before Jan 31, 2023 | N/A |
| Annual Bonus (2023 EICP) | Performance goals not formally approved for 2023 (bonuses determined discretionarily for NEOs) | 60% of base salary | Not disclosed for Dr. Stefan | Not disclosed | N/A |
Notes
- Executive Incentive Compensation Plan governs annual bonus opportunities; the Board/Compensation Committee sets objectives and determines payouts, with 2023 goals not formally approved for NEOs per proxy narrative. Dr. Stefan’s 2023 bonus amount is not disclosed in available filings .
Equity Ownership & Alignment
Assumed options (post Amprius Holdings liquidation and option assumption)
| Grant Date | Shares Underlying Assumed Options | Exercise Price ($) | Expiration Date | Vesting Status | Notes |
|---|---|---|---|---|---|
| 03/17/2015 | 3,471 | 0.98 | 03/17/2025 | Fully vested | Exercised before expiration |
| 03/16/2017 | 41,653 | 0.62 | 03/15/2027 | Fully vested | — |
| 12/16/2021 | 139,613 | 3.68 | 12/15/2031 | Fully vested | — |
Shares received from Amprius Holdings liquidation
| Date | Shares Received | Context |
|---|---|---|
| 10/23/2024 | 52,962 | Liquidating Distribution from former majority stockholder; Company assumed and adjusted options, all Assumed Options fully vested |
Beneficial ownership at Closing (post-business combination)
| Date | Beneficial Ownership (Shares) | % of Outstanding | Notes |
|---|---|---|---|
| 09/16/2022 | 825,008 | 1.0% | Consists of options exercisable within 60 days; outstanding shares referenced total 84,168,916 at Closing |
Hedging and pledging policies
- Company insider trading policy prohibits hedging (e.g., collars, swaps, exchange funds) and pledging/margin accounts by employees and directors, including executive officers .
Employment Terms
| Agreement | Effective Date | Base Salary | Target Bonus | Equity Eligibility | At-Will | Other Terms |
|---|---|---|---|---|---|---|
| Confirmatory Employment Letter | Signed Sep 12, 2022 | $250,000 | 30% of base salary | Eligible for stock options/RSUs under Company plans | Company maintains at-will employment policy | Full-time CTO reporting to CEO; bonus subject to Board/Committee objectives |
- Severance/change-in-control: Proxy disclosures detail severance terms for other executives (Sun, Wallach, Bornstein) but do not provide Stefan-specific severance terms in the available excerpts. Equity awards under the 2022 Equity Incentive Plan may be assumed, accelerated, terminated, or cashed out upon change in control as determined by the plan administrator .
Compensation Committee and Governance Context
- Compensation Committee: Members include Dr. Wen Hsieh (Chair), Donald R. Dixon, and Mary Gustanski; all independent under SEC/NYSE rules .
- Consultant: Compensia engaged to advise on executive compensation and peer group development; committee assessed independence and reported no conflicts .
- Emerging Growth Company status: Company follows smaller reporting company disclosure; not required to hold say‑on‑pay/say‑on‑frequency votes while EGC status applies .
Investment Implications
- Incentive alignment: Stefan’s target bonus increased from 30% to 60% with a base salary increase effective January 1, 2023, indicating higher at‑risk cash compensation tied to performance objectives under the EICP, which can tighten pay‑for‑performance linkage if goals are codified going forward .
- Liquidity and selling pressure: All Assumed Options are fully vested, and Stefan received 52,962 shares from the Amprius Holdings liquidation; while this creates potential liquidity, the company’s insider trading policy prohibits hedging and pledging, mitigating forced‑sale risk signals .
- Retention risk and change‑of‑control: Lack of disclosed Stefan‑specific severance economics in the available filings reduces visibility on retention and transaction outcomes; however, plan‑level change‑in‑control provisions provide for potential option acceleration or other treatments that can act as retention/transaction incentives .
- Ownership alignment: Historical beneficial ownership (1.0% at Closing, largely options) and fully vested options plus distribution shares indicate material equity exposure to AMPX outcomes, supporting alignment with shareholders .