Amprius Technologies (AMPX) shifts CEO role to Tom Stepien as Kang Sun becomes advisor

Rhea-AI Filing Summary

Amprius Technologies announced a leadership transition. Chief Executive Officer Dr. Kang Sun told the board he will step down from his officer role effective December 31, 2025, and become Executive Advisor on January 1, 2026, while remaining on the board. The company states his decision is not due to any disagreement over operations, policies, or practices.

Amprius entered into a new employment agreement with Dr. Sun, giving him a $633,000 annual salary without bonus eligibility and providing six months of salary continuation and partial accelerated equity vesting if he is terminated without cause, resigns for good reason, or upon death or disability, with full stock option vesting if this occurs in connection with a change in control. Current President Tom Stepien has been appointed Chief Executive Officer effective January 1, 2026, with a $633,000 base salary, a target annual cash bonus equal to 100% of salary, and a grant of 200,000 restricted stock units that vest over four years.

Insights

Corporate governance and compensation analyst

Amprius restructures leadership as CEO moves to advisor role and president becomes CEO with new equity package.

Amprius Technologies is transitioning leadership as Dr. Kang Sun steps down as Chief Executive Officer on December 31, 2025, moving to an Executive Advisor role and remaining on the board. The company states his decision is not due to any disagreement about operations, policies, or practices, which helps frame this as an orderly transition rather than a conflict-driven change.

The amended employment agreement grants Dr. Sun an annual salary of $633,000 with no annual bonus, while preserving his ability to vest in existing equity awards so long as he continues service. If his employment ends without Cause, for Good Reason, or due to death or disability, he is eligible for six months of base salary continuation and accelerated vesting of the portion of equity that would vest over the next six months, with full stock option acceleration if this occurs upon or within six months after a Change in Control.

Current President Tom Stepien becomes Chief Executive Officer on January 1, 2026 with a base salary of $633,000, a target annual cash bonus equal to 100% of salary, and 200,000 restricted stock units granted on December 19, 2025. The RSUs vest 25% on the first quarterly vesting date on or after the one-year anniversary of grant, then quarterly over three years, tying a meaningful equity stake to his continued employment and long-term company performance.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

_________________________

FORM 8-K

_________________________

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): December 18, 2025

_________________________

Amprius Technologies, Inc.

(Exact name of Registrant as Specified in Its Charter)

_________________________

Delaware			001-41314			98-1591811
(State or Other Jurisdiction of Incorporation)			(Commission File Number)			(IRS Employer Identification No.)

1180 Page Ave Fremont, California			94538
(Address of Principal Executive Offices)			(Zip Code)

Registrant’s Telephone Number, Including Area Code: (800) 425-8803

N/A

(Former Name or Former Address, if Changed Since Last Report)

_________________________

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

			o			Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
			o			Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
			o			Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
			o			Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common stock, par value $0.0001 per share

AMPX

The New York Stock Exchange

Redeemable warrants, each exercisable for one share of common stock at an exercise price of $11.50

AMPX.W

The New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company x

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

Item 5.02 Departure of Directors or Principal Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On December 18, 2025, Dr. Kang Sun, the Chief Executive Officer of Amprius Technologies, Inc. (the "Company") informed the Company's Board of Directors (the "Board") of his intention to step down from his officer position, effective as of December 31, 2025. Dr. Sun will assume the position of Executive Advisor of the Company on January 1, 2026. Dr. Sun will continue to be a member of the Board. Dr. Sun's decision to step down is not the result of any disagreement regarding any matter relating to the Company's operations, policies or practices.

The Company has entered into an amended and restated employment letter agreement with Dr. Sun, effective January 1, 2026 (the "Employment Agreement"). The Employment Agreement provides that Dr. Sun's employment is at-will and may be terminated by either Dr. Sun and the Company at any time and for any reason. Pursuant to the Employment Agreement, Dr. Sun will receive an annual salary of $633,000 and will not be eligible to receive any annual bonus or participate in any annual bonus program of the Company. Dr. Sun will remain eligible to vest in any and all his outstanding equity awards in respect of shares of the Company in accordance with the terms thereof, subject to Dr. Sun's continued service to the Company under the terms of the Employment Agreement through the applicable vesting dates.

Pursuant to the Employment Agreement, if Dr. Sun's employment is terminated by the Company other than for Cause (as defined in the Employment Agreement), or by Dr. Sun for Good Reason (as defined in the Employment Agreement) or as a result of Dr. Sun’s death or disability, in any such case, Dr. Sun will be eligible to receive severance benefits in the form of base salary continuation for a period of six months following the date of termination, subject to his execution of an effective release of claims, and the unvested portion of his then-outstanding equity awards that would normally vest over the following six months from the date of termination will immediately vest prior to such termination and become exercisable; provided, that if such termination occurs upon or within six months following the closing of a Change in Control (as defined in the Employment Agreement), all outstanding stock options then-held by Dr. Sun will immediately vest and become exercisable.

The foregoing description does not purport to be complete and is subject to, and qualified in its entirety by, the complete text of the Employment Agreement, a copy of which will be filed as an exhibit to the Company’s Annual Report on Form 10-K for the fiscal period ending December 31, 2025.

The Company's current President, Mr. Tom Stepien, 64, has been appointed Chief Executive Officer of the Company, effective as of January 1, 2026. Mr. Stepien will receive an annual base salary of $633,000 and will be eligible to earn an annual cash bonus, with a target amount equal to 100% of his base salary, based on the achievement of performance goals established by the Board or the compensation committee of the Board in its sole discretion.

In connection with his appointment as Chief Executive Officer, the Compensation Committee approved a grant to Mr. Stepien of an award of 200,000 restricted stock units, with a grant date of December 19, 2025, covering shares of the Company's common stock pursuant to the Company's 2022 Equity Incentive Plan and a grant agreement entered into between the Company and Mr. Stepien. The award will vest as to 25% of the total number of restricted stock units granted on the first quarterly vesting date of the Company on or immediately following the one-year anniversary of the grant date, and the remainder will vest quarterly over three years thereafter, subject to Mr. Stepien's continuous employment with the Company on each applicable vesting date.

Mr. Stepien joined the Company as President in May 2025. Prior to joining the Company, Mr. Stepien served as Chief Executive Officer of South 8 Technologies, a provider of novel electrolyte for lithium-ion batteries, from August 2023 to March 2025; from December 2020 to July 2023, he was an Operating Partner at KCK Group, a private equity firm focused on industrial technologies. Mr. Stepien also co-founded and led Primus Power, a long-duration stationary storage company in 2009. Earlier in his career, he held leadership roles at Applied Materials, the global semiconductor equipment leader.

The selection of Mr. Stepien was not pursuant to any arrangement or understanding between him and any other person. There have been no transactions since the beginning of the Company’s last fiscal year, and there are no currently proposed transactions, in which the Company was or is to be a participant and in which Mr. Stepien or any member of his immediate family had or will have any material interest that are required to be reported under Item 404(a) of Regulation S-K.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

						AMPRIUS TECHNOLOGIES, INC.
Date: December 22, 2025			By:			/s/ Ricardo C. Rodriguez
						Name: Ricardo C. Rodriguez
						Title: Chief Financial Officer

FAQ

What leadership change did Amprius Technologies (AMPX) disclose in this 8-K?

Amprius disclosed that Chief Executive Officer Dr. Kang Sun will step down from his officer position effective December 31, 2025, become Executive Advisor on January 1, 2026, and remain on the board. Tom Stepien, currently President, has been appointed Chief Executive Officer effective January 1, 2026.

Did Amprius Technologies say why Dr. Kang Sun is stepping down as CEO?

The company stated that Dr. Sun informed the board of his intention to step down and specifically noted that his decision is not the result of any disagreement regarding the company’s operations, policies, or practices.

What are the key terms of Dr. Kang Suns new employment agreement with Amprius (AMPX)?

Under the amended and restated employment agreement effective January 1, 2026, Dr. Sun’s employment is at-will, he receives an annual salary of $633,000, is not eligible for any annual bonus, and remains eligible to vest in all outstanding equity awards subject to his continued service. If terminated without Cause, for Good Reason, or due to death or disability, he is eligible for six months of base salary continuation and accelerated vesting of equity that would vest over the following six months, with full stock option vesting if such termination occurs upon or within six months after a change in control.

What compensation will new CEO Tom Stepien receive at Amprius Technologies?

As Chief Executive Officer, Mr. Stepien will receive an annual base salary of $633,000 and will be eligible for an annual cash bonus with a target equal to 100% of his base salary, based on performance goals set by the board or its compensation committee.

What equity award did Amprius grant to new CEO Tom Stepien?

In connection with his appointment as Chief Executive Officer, Mr. Stepien received a grant of 200,000 restricted stock units on December 19, 2025 under the company’s 2022 Equity Incentive Plan. 25% of the RSUs vest on the first quarterly vesting date on or after the one-year anniversary of the grant date, and the remaining units vest quarterly over the next three years, subject to his continued employment.

Are there any related-party transactions involving Amprius and new CEO Tom Stepien?

The company states there have been no transactions since the beginning of the last fiscal year, and no currently proposed transactions, in which Amprius was or is to be a participant and in which Mr. Stepien or his immediate family had or will have a material interest that require disclosure under Item 404(a) of Regulation S-K.