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Spear Power Systems designs and manufactures safe, reliable lithium ion battery storage systems for demanding applications including defense, marine propulsion, oil & gas, and mining. Spear’s decades of experience and customer centric, electrochemistry agnostic approach maximizes value and reduces the time to deployment.

Leadership Team

Jeffery Kostos – Founder, President & CEO

Jeff has more than 25 years of experience in the fields of energy storage & energy management, both domestically and internationally, in the areas of business development, operations, marketing, sales management, and design engineering. Prior to founding Spear Power Systems, Jeff served as Executive VP of Dow Kokam LLC (now Xalt Energy LLC), a JV between The Dow Chemical Co. and Kokam America Inc. At Dow Kokam, Mr. Kostos was responsible for supporting Dow Kokam’s growth strategy with a focus on defense and industrial markets. Prior to Dow Kokam, Jeff was the COO of Kokam America Inc., a company he co-founded in 2005. Here, he helped lead both the efforts to establish one of the first lithium polymer manufacturing facilities in the U.S, as well as take primary responsibility for leading profitable top line growth for the company.

Mr. Kostos began his professional career as a Design Engineer for a refrigeration company, where he received 5 patents. Mr. Kostos then joined the battery industry with GNB Technologies Inc. in 1991 where he held positions of increasing responsibility and transitioned from Engineering to International Business Development where, after moving to Belgium, he led the establishment of GNB’s European HQ and subsequently several regional sales offices, and a production facility in Douai France.   In 2000, while still in Europe, Jeff joined EnerSys as President of European Operations and led a dual strategy of organic growth and growth through acquisition. In 2002 Jeff moved back to the US as Vice President Sales & Marketing to lead EnerSys’ $180M North American Reserve Power business unit.

Mr. Kostos holds a BS in Mechanical Engineering from Bradley University, an MBA from Loyola University of Chicago, and is an Executive Development Program Graduate from University of Melbourne in Australia.

Joon Kim, Ph. D. – Co-founder and Chief Technology Officer (CTO)

Joon served as Vice President of Technology at Dow Kokam LLC since its inception in 2009. He was CTO and a co-founder of Kokam America Inc. He has been involved in Kokam Superior Lithium Polymer Battery (SLPB) technology since its early stage development and implementation of mass production. In addition to his responsibilities as CTO of the company, he assumed overall project management roles for SLPB technology transfer from both Kokam to Kokam America Inc. when the 8Ah cell production line was installed in Lee’s Summit, MO, and from Kokam to Dow Kokam where he oversaw the transfer of the 600MWh technology transfer to the state of Michigan. He performed the following duties for the 600 MWh project; ‘define project scope and processes’, ‘set equipment performance specifications’, ‘coordinate with Kokam Co. Ltd. equipment engineering team’, ‘allocate budget and plan resources’, ‘oversee equipment installation and equipment performance proving-in work’, ‘source raw materials’ and ‘define quality control points and issues’ until daily operation was handed over to operations.

Prior to founding Kokam America Inc, in 2005, Dr. Kim was Vice President of Li-ion Battery Sales & Marketing at Eagle Picher Inc.. He also held various leadership positions for development of Li-S rechargeable battery at Sion Power Corporation in Tucson, Arizona. Formerly, Dr. Kim was a Staff Research Associate at Lawrence Berkley National Laboratory working on materials for lithium rechargeable batteries. He was also Director of Corporate R&D Analytical Laboratory and a Research Group Leader conducting research and development projects on conducting polymers, surface/interface phenomena, and solid gel chemistry at LG Chemical in Korea. He has over 20 years of direct battery business experience of material development, sales and marketing, and project management. In addition, he has 12 years of business experience of energy industries including battery raw materials at LG Chem.

Dr. Kim has a Ph.D. in chemistry with emphasis in electrochemistry from the University of Illinois at Urbana-Champaign and a B.S. with Cum Laude in chemistry from Seoul National University, Korea. Dr. Kim is also fluent in Korean.

Mitch MabreyVice President Business Development & Engineering

Mr. Mabrey, a Founding Member of Spear Power Systems, will lead the teams business development activities with a strong focus on pipeline and sales channel development. Additionally, he will be responsible for the strategic direction and execution of Spear’s integrated energy storage and power delivery solutions for defense and industrial markets.

Mr. Mabrey joined Dow Kokam in 2010 where he has managed the product development and application engineering teams in addition to incubating the utility grid storage market where he secured over $10 million of initial business within a 6 month period of time.

Mr. Mabrey has over 10 years of experience in electromechanical design, test, applications engineering, information technology, and business development with several companies including Accenture and Honeywell FM&T. Mitch also served as a US Foreign Service officer for the U.S. State Department in Guyana and France.

Mr. Mabrey received a BS in Mechanical Engineering from the Illinois Institute of Technology and is fluent in French.

Daryll Nottingham – Director Business Operations & Contracts

Ms. Nottingham, a Founding Member of Spear Power Systems, will utilize her expansive experience with Government contracts and negotiating to lead Spear’s Contracts Administration with particular focus on Spear’s defense related contracts, technology agreements and partnerships. Daryll will also lead Spear’s business operations by implementing best in class processes that align with the scale and scope of the business over time.

Ms. Nottingham joined the team in October 2012 where she served as lead negotiator and administered business arrangements with the Government, including contracts, grants, cooperative agreements and technology investment agreements. Prior to joining, Ms. Nottingham enjoyed a 30-year career with the U.S. Government managing contracting organizations and providing support worldwide during peacetime, conflict and war. Her expertise includes developing, negotiating and administering contracts to support research and development, new and existing program development and deployment, construction and services that ranged from fixed price to variations of cost, including incentive arrangements with progressive targets that spanned long durations and totaled billions of dollars. Ms. Nottingham’s expertise enabled her to craft customer-unique, broad-scoped arrangements that implemented acquisition reform and efficiency initiatives, including those that she devised and were later adopted across the organization. Her efforts have been recognized through numerous achievement awards, including three Meritorious Civilian Service Awards, recognition from six of the ten Combatant Commands and numerous Commander’s Awards.

Ms. Nottingham earned a Bachelor of Science degree from Regis University, where she is also completing her Master’s degree in International Business. She is Level III certified in contracting and is an active member of the Army Acquisition Corps.


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Spear opens new engineering, cell distribution, battery pack assembly, and solution integration facility in Lee’s Summit, MO USA.

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Spear Power Systems formed by former Kokam America Founders Jeff Kostos & Dr. Joon Kim.

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Dow Kokam buys the assets of Kokam America

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Kokam America opens first lithium polymer cell manufacturing facility in the U.S.