Kemiwatt: redox flow batteries
Kemiwatt is a French startup founded in 2014 that develops redox flow batteries with organic electrolytes.
Kemiwatt battery technology
Batteries are a mode of electricity storage that has several problems: they need a lot of materials, there are safety issues (risk of fire) and they are not suitable for long-term storage.
Redox flow batteries solve these problems. Electricity is stored in solutions, so their storage capacity depends on the size of their reservoirs. There are no (or few?) fire hazards, and electricity can be stored for a long time without being lost. One of their current problems is the nature of these solutions. In particular, they use vanadium, an unusual metal, in an acid electrolyte.
Kemiwatt’s innovation consists in using electrolytes that are biodegradable: a solution of aluminum ions (Al2 / Al3 couple) and one of carbon ions (C3 /C2 ).
The reaction takes place inside graphite felts separated by a proton exchange membrane.
This battery could last more than 10,000 cycles, would require little maintenance and would have a long service life of over 20 years(source)
Progress and funding
The technology was initially developed by Didier Floner and Florence Geneste at the University of Rennes 1 laboratory. In 2014, they teamed up with François Huber to create Ionwatt and raised €1.4m through Demeter Partner and GO Capital. The company develops a 10-20kW prototype in 2016 and raises €1.2m from the same investors. In 2017, it renamed itself Kemiwatt [rq: obviously there was a float on the name, which is displayed as “Kemwatt” in several media] and developed a demonstrator of up to 30kW.(source) They raised €2M, again from the same investors, in 2018, bringing the total to €4.4M.(source)
They would have been backed by Demeter Ventures, GO CAPITAL, Pierre-Yves Divet [presents himself as “non-executive director” since 2018 on Linkedin] and SATT Ouest Valorisation.
Since 2018, the company’s president is Guillaume Chazalet.
- Interview with F.Huber in 2017 on the interest of redox flow batteries: https://lenergeek.com/2017/08/04/stockage-energie-batteries-redox-flow-kemwatt/
- A comprehensive presentation of the project: https://www.energystream-wavestone.com/2018/10/interview-rencontre-avec-kemiwatt-une-startup-qui-fabrique-des-batteries-a-electrolytes-biodegradables/