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R. S. Kalb
the commercial scale, as optical brighteners in display applications, and as process
chemicals for the purification of electronic display materials.
Due to their high electrochemical stability, negligible vapor pressure and flammability, and tunable solvation properties for the dissolution of electrochemically active
species, a large number of implemented ionic liquid applications involve electrolytes. Several companies use ionic liquids on the pilot scale for electroplating and
electropolishing metals, such as aluminum (IoLiTec, Scionix, C-Tech Innovation).
Another company, Xtalic, relies on ionic liquids for the production of nanostructured
aluminum alloys and plans to commercialize the process in 2019. Many electrolyte
applications are energy-related, such as dye-sensitized solar cells (G24 Power, H.
Glass), lithium-ion batteries (NOHMs, Pionics), zinc–air batteries (NantEnergy), or
supercapacitors (Panasonic, ZapGo). Other applications include electrolytes for gas
sensors (IoLiTec, Novasina) and electrochromic windows (IoLiTec). Even though
most of the applications are quite expensive due to the very high purity requirements
and the fluorine chemistry costs of the anion, ionic liquids electrolytes are competitive due to the significantly increased performance and safety. The higher added
value of the final industrial and consumer end products is justified.
Despite the hundreds of papers and patent applications in the field of ionic liquid lubricants that can be found in literature—many of them attributing excellent
tribological properties—there are only two niche products on the market. Klüber
Lubrication offers electro-conductive lubricants that prevent electro-erosion in roller
bearings, and proionic produces a lubricant for high-pressure gas compression.
Both applications are commercialized. This finding seems to reflect the competitiveness of the commercial lubricant sector, especially when considering state-ofthe-art lubricants with specialized functional applications. Moreover, lubricant R&D
is sophisticated and expensive, and many critical parameters are met largely by
empiricism.
Six engineering applications have been implemented using ionic liquids as operating fluids. New working pairs based on ionic liquids and water or alcohols are
operated by Evonik (under a BASF license) at the pilot level for absorption chillers
or heat pumps. The fluids show less corrosion, lower toxicity, lower flammability,
and no crystallization compared to conventional working pairs (e.g., based on LiBr
and water). This technology was invented and originally developed by IoLiTec, and
in 2014, a patent application was filed by BASF. Ionic liquids for ILDAC applications (ionic liquid desiccant air conditioning), with water being the refrigerant, were
developed at proionic and were piloted in the multi-100 kg scale. This process places
the ionic liquid in direct contact with breathable air and is, therefore, an open sorption
process. In addition to similar advantages over conventional systems, as described
above for absorption chillers, the desiccant air-conditioning system requires lowered energy input. A comparable ILDAC system was developed at the pilot stage by
Evonik.
The first implementation of an engineering ionic liquid is the well-known “ionic
compressor” invented by Linde and proionic in 2005 and commercialized by Linde
and Flowserve in a joint venture. This compressor uses an ionic liquid piston and
sealing systems for the high compression of, for example, hydrogen gas or natural
R. S. Kalb
the commercial scale, as optical brighteners in display applications, and as process
chemicals for the purification of electronic display materials.
Due to their high electrochemical stability, negligible vapor pressure and flammability, and tunable solvation properties for the dissolution of electrochemically active
species, a large number of implemented ionic liquid applications involve electrolytes. Several companies use ionic liquids on the pilot scale for electroplating and
electropolishing metals, such as aluminum (IoLiTec, Scionix, C-Tech Innovation).
Another company, Xtalic, relies on ionic liquids for the production of nanostructured
aluminum alloys and plans to commercialize the process in 2019. Many electrolyte
applications are energy-related, such as dye-sensitized solar cells (G24 Power, H.
Glass), lithium-ion batteries (NOHMs, Pionics), zinc–air batteries (NantEnergy), or
supercapacitors (Panasonic, ZapGo). Other applications include electrolytes for gas
sensors (IoLiTec, Novasina) and electrochromic windows (IoLiTec). Even though
most of the applications are quite expensive due to the very high purity requirements
and the fluorine chemistry costs of the anion, ionic liquids electrolytes are competitive due to the significantly increased performance and safety. The higher added
value of the final industrial and consumer end products is justified.
Despite the hundreds of papers and patent applications in the field of ionic liquid lubricants that can be found in literature—many of them attributing excellent
tribological properties—there are only two niche products on the market. Klüber
Lubrication offers electro-conductive lubricants that prevent electro-erosion in roller
bearings, and proionic produces a lubricant for high-pressure gas compression.
Both applications are commercialized. This finding seems to reflect the competitiveness of the commercial lubricant sector, especially when considering state-ofthe-art lubricants with specialized functional applications. Moreover, lubricant R&D
is sophisticated and expensive, and many critical parameters are met largely by
empiricism.
Six engineering applications have been implemented using ionic liquids as operating fluids. New working pairs based on ionic liquids and water or alcohols are
operated by Evonik (under a BASF license) at the pilot level for absorption chillers
or heat pumps. The fluids show less corrosion, lower toxicity, lower flammability,
and no crystallization compared to conventional working pairs (e.g., based on LiBr
and water). This technology was invented and originally developed by IoLiTec, and
in 2014, a patent application was filed by BASF. Ionic liquids for ILDAC applications (ionic liquid desiccant air conditioning), with water being the refrigerant, were
developed at proionic and were piloted in the multi-100 kg scale. This process places
the ionic liquid in direct contact with breathable air and is, therefore, an open sorption
process. In addition to similar advantages over conventional systems, as described
above for absorption chillers, the desiccant air-conditioning system requires lowered energy input. A comparable ILDAC system was developed at the pilot stage by
Evonik.
The first implementation of an engineering ionic liquid is the well-known “ionic
compressor” invented by Linde and proionic in 2005 and commercialized by Linde
and Flowserve in a joint venture. This compressor uses an ionic liquid piston and
sealing systems for the high compression of, for example, hydrogen gas or natural