SunGreenH2, a Singapore-based cleantech company founded in 2020, develops low-cost and high-performance electrodes for water electrolyzers. The electrodes reduce the use of platinum group metals and feature a high catalytic surface area. They can be directly used in commercial water electrolyzers today to achieve cost-effective green hydrogen production.
Challenges: hydrogen fuel
Green hydrogen (H₂) is a crucial element of the future net-zero world. Using electricity from renewable sources, such as nuclear, solar, and wind, to split water produces green hydrogen. Green hydrogen can decarbonize hard-to-abate industries, such as steel manufacture, long-distance transportation, shipping, and aviation. Seasonally, it can also store renewable electricity and serve as a chemical feedstock.
There are several ways to use electricity to turn water into hydrogen right now. These include alkaline electrolyzers, proton exchange membrane (PEM) electrolyzers, anion-exchange membrane (AEM) electrolyzers, and solid oxide electrolysis cells.
One problem with electrolyzer systems for making hydrogen is that their performances don’t last very long, and the electrode materials used are very expensive. There is a push to reduce the use of platinum group metals or completely get rid of the need for platinum group metals by making other electrode catalysts without compromising their performance.
SunGreenH2 Technology
SunGreeH2 has developed an electrode fabrication technology that uses 30 times less platinum group metals. The electrodes have a high catalytic surface area, which is achieved through micro- and nanofabrication technology. Electrolyzers employing SunGreeH2’s electrodes have an increased current density, a reduced operation voltage, and long-term stability compared to conventional electrolyzers.
SunGreenH2 electrode fabrication
The diagram below illustrates SunGreenH2’s electrode fabrication processes.
- Electrode substrate pretreatment
An electrode substrate is made of nickel foam or other metals, such as nickel alloy and titanium. The electrode substrate is cleaned to remove oil, grease, and native oxide. It is then electrochemically activated.
- Composite material deposition
The completely cleaned and dried electrode substrate is deposited with a layer of composite material via sputtering or electrodeposition. This composite material layer is composed of a catalyst and a sacrificing material.
The catalyst material is NiPt or other metals. The sacrificing material is aluminum (Al), zinc (Zn), or other metals. The sacrificing metal has a lower electrochemical potential as compared to the catalyst. The sacrificing metal is leached out by selective etching in the late leaching process.
The catalyst and sacrificing materials are simultaneously deposited on the surface of the electrode. This allows the formation of alloys using up to ten times less platinum group metals while showing a higher degree of catalytic activity compared to a conventional electrode.
Simultaneous deposition in the suppetering process is done by using a compound target. In the electrochemical deposition process, this is done by electroplating the electrode substrate in a mixed salt compound solution.
- Etching
The sacrificing material in the composite material layer is leached. This results in the formation of a microporous and nanoporous structure within the electrode. The leached sacrificing materials leave pores within the compound material. The formation of the microporous and nanoporous structure increases the active area of the catalyst and, thereby, the catalytic activity of the electrode. This also reduces the amount of catalytic material required to manufacture the electrode.
- Dopping
The leached electrode is doped by introducing a doping agent, such as nitrogen, phosphorus, sulfur, boron, molybdenum, iron, chromium, cobalt, or copper. The doping agent reduces the electrochemical potential of the electrode. This reduces the electrolyzers’ operating voltage and energy consumption.
The doping agents can be dissolved in an electrolyte solution and incorporated into the electrode by applying an electrical potential. The doping agent can also be added to the electrode by co-deposition in sputtered compound material by employing a reactive gas during sputtering.
- Thermal treatment
The electrode is thermally treated in a vacuum to improve performance.
SunGreenH2 Patent
- WO2023003509A3 Electrolyser system and method of electrode manufacture
SunGreenH2 Technology Applications
- electrolyzers for hydrogen production
SunGreenH2’s electrodes are applicable to almost all commercially available electrolyzers today. By dramatically increasing the available surface area for the electrolysis reaction, the electrodes can double hydrogen production while consuming 20% lower renewable energy compared to conventional electrolyser components.
The electrodes reduce the use of platinum group metals by an order of magnitude lower than the current industry standard. This reduction in precious metal use is particularly important for the sustainability and scalability of green hydrogen production.
SunGreenH2 Products
SunGreenH2 manufactures high-performance electrodes for commercially available electrolyzers.
SunGreenH2 Funding
SunGreenH2 has raised a total of $4.5M in funding over 9 rounds:
- five seed rounds
- two grant rounds
- two Non-equity Assistance rounds
Their latest funding was raised on Jun 20, 2023 from a Non-equity Assistance round.
SunGreenH2 Investor
SunGreenH2 is funded by 12 investors:
- HAX
- Creative Destruction Lab
- SOSV
- Startupbootcamp Australia
- PETRONAS FutureTech
- Entrepreneur First
- BloombergNEF
- SGInnovate
- Sabancı Ventures
- Vinci Venture Capital
- Startup SG
- CAP Vista
PETRONAS FutureTech and Sabancı Ventures are the most recent investors.
SunGreenH2 Founder
Tulika Raj and Saeid Masudy Panah are Co-Founder.