Koem Co., Ltd. is an unlisted company specializing in winding equipment, manufacturing the core equipment for forming cylindrical battery jelly rolls.
1. Company Overview
- Company name: Koem Co., Ltd.
- Business area: specializing in cylindrical secondary battery winders
- Listing status: unlisted
- Founder: Lee Gye-seol (holds roughly 93% equity, source: The Elec)
2. History and Personnel
The company presents itself as a ‘world-class winding equipment specialist,’ introduced as a firm that exclusively manufactures machines required for winding operations. Its core product is the winder equipment that forms a jelly roll in cylindrical battery manufacturing by winding the cathode, anode, and separator around a mandrel, similar to winding a roll of paper around a core.
The company maintains a specialist structure focused solely on winding equipment. Detailed organizational/personnel composition is (undisclosed).
According to The Elec, Koem operates as “a kind of family company” with founder Lee Gye-seol holding the vast majority (about 93%) of equity, and reportedly has expanded its business using its own capital without outside investment (source: The Elec).
3. Core Technology and Key Equipment
The company specializes in winding technology, the core process in cylindrical cell manufacturing. Detailed specifications are (undisclosed).
According to a 2026 report by The Elec, Koem supplied tabless-structure winders for Tesla’s 46800-format cylindrical cells (46mm diameter, 80mm height) to a pilot line at Tesla’s Fremont, California plant (source: The Elec, article No. 8701). The tabless design has the electrode contacting the current collector plate across the full width of the jelly roll, which the industry generally understands to require tighter tension uniformity and alignment precision during winding than conventional tab designs (general industry understanding; Koem’s actual tolerance figures are undisclosed).
- Winder for cylindrical batteries — core product
- Specialized equipment for the jelly-roll forming process
4. Production Infrastructure and Quality Assurance
Production capacity, factory floor area, and similar details are (undisclosed). Given the company’s structure as an unlisted family business, formal IR materials and regular disclosures are limited, and quantitative information in this profile is limited to what can be confirmed through the company website and media coverage such as The Elec.
5. Delivery Track Record and Partnerships
The company is reportedly used by Tesla, Samsung SDI, LG Energy Solution, and others, according to industry sources (based on third-party compiled data). Individual contract details are (undisclosed).
Koem’s primary customer is Samsung SDI, cited in industry coverage as the company that most extensively adopts Koem’s winder equipment (source: The Elec). A trading relationship with LG Chem has also been reported, though detailed volumes and contract terms are undisclosed (same source).
The specific scale of the Tesla supply agreement is undisclosed, but The Elec reported an estimate of roughly KRW 10 billion for the pilot-line volume (source: The Elec). Koem is reported to have maintained a long-standing trading relationship with Samsung SDI (same source), and industry observers have floated the possibility of additional orders if Tesla expands to mass-production lines (estimate; industry outlook, not a confirmed contract).
6. Financial Status and Roadmap
Although unlisted, figures cited in a The Elec report indicate revenue rose from KRW 32.6 billion in 2017 to KRW 47.2 billion in 2018, before sharply declining to KRW 11.2 billion in 2019 (source: The Elec, citing external data). In 2018 the company recorded an operating profit of KRW 5.6 billion on revenue of KRW 47.2 billion, an operating margin above 10%, but reportedly swung to an operating loss in 2019 (same source). The most recent financial figures are (undisclosed).
A specific roadmap is (undisclosed), though The Elec reported that the company’s stable earnings structure means there is little urgency for an IPO (source: The Elec). Given the founder’s high equity stake in this family-business structure, Koem may be more likely to continue an order-growth strategy centered on existing customers such as Samsung SDI rather than pursue outside capital (estimate, based on ownership structure and transaction history). As a specialist in R2R winding equipment, demand growth is plausible as adoption of larger-format cylindrical cells such as the 46800 format expands, though this reflects a general industry trend rather than a confirmed Koem expansion plan (estimate).
This profile was compiled from publicly available sources including the company’s website (koem.com) and INFO-EVERYTHING’s compiled data on secondary battery equipment makers; unverified figures and non-public information have not been arbitrarily included.