Achieved as the 'World's First'... Vanadium Ion Battery Developed That Maintains Performance for Decades and Is Fireproof [Digging Energy]

Specialist Report
World’s First Development of Vanadium Ion Battery (VIB)
On-site at Standard Energy’s R&D Facility

On the 16th of last month, at the headquarters of Standard Energy in Yuseong, Daejeon, a large black rectangular box caught my eye as I entered the CEO's office. On top of the box, which resembled a living room TV cabinet, was a model of a typical Energy Storage System (ESS) produced by the company.

Energy storage system (ESS) produced using vanadium ion batteries at the Standard Energy pilot line. Provided by Standard Energy

"The black box below is actually an ESS," explained Kim Bug-gi, the CEO of the company, without whose explanation I might not have noticed its true identity. Kim confidently said, "We deliberately designed it to look like a TV cabinet. ESS is now entering the era of becoming a home appliance."

Although secondary batteries have become widespread, especially in electric vehicles, many consumers still worry about fire hazards. ESSs that use batteries also occasionally experience fire accidents. However, there is a company that aims to place ESSs in various buildings and homes. That company is Standard Energy, which develops Vanadium Ion Batteries (VIB). Their tile-shaped ESS called ‘Energy Tile’ won an innovation award at CES 2025, the world's largest electronics and IT exhibition held in Las Vegas this January.

A typical ESS model is placed on top of a home energy storage system (Home ESS) developed by Standard Energy. Photo by Kang Hee-jong

During the interview, CEO Kim said, "We have confirmed that there is sufficient demand for VIB," and added, "We plan to establish a mass production line by March, ramp up production, and start full-scale manufacturing from June."

‘Easily Accessible Material’ Vanadium

VIB’s biggest feature is its safety from fire because it uses water as the electrolyte. Different types of vanadium compounds are applied to the cathode and anode. During charging and discharging, vanadium ions and water undergo a chemical reaction. The principle is that cations move through a separator to enable charging and discharging.

The prototype of VIB is the Vanadium Redox Flow Battery (VRFB). However, structurally, VIB is completely different from VRFB. VRFB stores vanadium electrolyte in a separate storage tank and circulates it using a pump. In contrast, VIB uses microfluidics technology, so no pump is needed. VRFB requires tanks and pumps, making it large, but VIB can be miniaturized.

CEO Kim initially developed VRFB when founding Standard Energy but gave up after four years. "VRFB inherently had energy efficiency limitations because it required a separate power source to operate the pump. After much consideration, we shifted our focus to developing VIB."

Kim Bugi, CEO of Standard Energy

Kim founded Standard Energy in 2013 at the age of 28 while working as a research assistant professor at KAIST, just six months after his appointment.

"I saw many good technologies ending as mere academic papers. I wanted many people to benefit from the technology I developed."

Kim focused on vanadium because it is an ‘easily accessible material.’ Although unfamiliar to the general public, vanadium is an essential mineral in the steel industry. Adding a small amount to steel increases its strength, making it useful in various industries. Vanadium also helps regulate cholesterol production and is taken as a nutritional supplement.

Kim emphasized, "Good technology should be accessible to many people and use materials that are easy to obtain. For the same reason, we do not use rare earth elements." The materials used in vanadium ion batteries are all easily accessible, although they have not been commonly used in batteries before. This also makes them less vulnerable to mineral weaponization by China.

Large Volume but High Output Advantage, Optimal for ESS

While VRFB has about 30 years of history, VIB was developed first in the world by Standard Energy. The company holds about 250 core patents related to this technology and is focusing on patent protection by recruiting specialized patent personnel.

VIB has four advantages: high efficiency, long lifespan, fire safety, and high output. According to Standard Energy, VRFB shows energy efficiency in the 80% range, while VIB boasts over 90% energy efficiency. It maintains performance even after more than 15 years of use. Laboratory tests have conducted over 100,000 charge-discharge cycles.

Basic structure of a vanadium redox flow battery. Provided by Standard Energy

Because VIB uses water as the electrolyte, it is safe from fire. According to a video released by the company, even drilling through VIB does not cause a fire. VIB also shows higher output compared to lithium-ion batteries. Based on the C-rate, which indicates battery charge-discharge capability, VIB performs at 5C (meaning it can be charged or discharged five times per hour per cell).

However, VIB has a larger volume, so its energy density is lower than that of lithium-ion batteries. This is why it is difficult to use VIB in electric vehicles.

The best application for VIB is in ESS. VIB is safe from fire, highly efficient, and has a long lifespan. Although its low energy density is a drawback, Kim explains that its high output sufficiently compensates for this.

Kim emphasized, "Compared to lithium-ion batteries, VIB has four times better output, so even with a smaller capacity, it can deliver excellent performance and is economically advantageous." For example, if a 2 kWh lithium-ion battery is needed to reduce a 1 kW peak power, VIB only requires 0.5 kWh capacity. From the customer's perspective, adopting VIB means expecting the same effect as lithium-ion batteries at a lower cost, with fire safety as a given.

"Not a Replacement for Lithium-ion Batteries, but Complementary"

Kim does not see VIB replacing lithium-ion batteries in the ESS market. He believes the markets are different.

"The title of our publicly announced business plan is ‘Divide the World into Two.’ It means that lithium-ion batteries and VIB will complement each other in the ESS market."

Lithium-ion batteries are suitable for applications requiring long-term electricity storage, while VIB is optimized for high-output applications. Initially, the ESS market needed only simple energy storage, but as the market has segmented, demand for high-output ESS has increased.

Typical cases include construction sites, data centers, and electric vehicle charging. At home, as heating, cooling, and kitchen appliances become electrified, the need for high-output ESS is growing. Standard Energy’s recently introduced tile-shaped ESS, ‘Energy Tile,’ targets this demand.

'Energy Tile' by Standard Energy, winner of the Innovation Award at CES 2025. Provided by Standard Energy

Standard Energy currently produces VIB at a pilot line and supplies it to some customers. This year, they plan to install VIB ESS at 12 sites, including overseas (Japan).

They are also preparing a mass production line called the ‘V-line’ to expand VIB production. Since VIB is the world’s first, they designed the mass production equipment themselves. Many founding members, including CEO Kim, majored in mechanical engineering at KAIST, making this possible. The production equipment is fully automated without human intervention. Kim explained, "The equipment manufacturer is currently finishing assembly, and the yield rate during test operation is about 95%." Once the production line is complete, production capacity is expected to increase ninefold.

Standard Energy is also conducting investment attraction in line with product mass production. Kim said, "We are negotiating with major investors who can participate in the business, not just for funding." Lotte Chemical invested 65 billion KRW in 2022, holding a 15% stake in the company.

"Over 140,000 Charge-Discharge Tests... No Cooling System Needed for ESS"

Visiting the R&D center at Standard Energy’s headquarters, I saw vanadium ion battery charge-discharge tests being conducted in a room resembling a large server room. Lee Dong-young, CTO of Standard Energy, explained, "We are conducting charge-discharge tests on about 1,000 vanadium ion batteries under different conditions."

The battery tested the longest showed 145,131 charge-discharge cycles. Lee said, "Even after more than 140,000 cycles, it maintains over 90% efficiency." Assuming two charge-discharge cycles per day, this means the battery can maintain performance for 200 years. Vanadium ion batteries are chemically very stable, theoretically allowing almost unlimited use. However, Standard Energy conservatively estimates the battery life at 15 to 20 years. The battery operates normally within a temperature range of -20 to 50℃.

I also visited the vanadium ion battery pilot line about five minutes by car from the headquarters. On the first floor of the pilot line, stacking equipment automatically assembled vanadium ion battery cells nonstop. The cells assembled on the second floor were connected in groups of 50 with bus bars and packaged on the first floor. The second floor was restricted to outsiders.

The semi-finished vanadium ion battery packs then underwent inspection before being moved to an adjacent building for ESS assembly. Yang Won-jun, head of manufacturing at Standard Energy, explained, "We develop the Battery Management System (BMS) ourselves and produce the ESS."

ESS using vanadium ion batteries has a much simpler structure than existing lithium-ion battery ESS. It also appeared very compact externally. Yang explained, "Lithium-ion battery ESS requires various safety devices and cooling systems to prevent thermal runaway, but vanadium ion batteries do not need these, allowing for a simpler structure."