1 Introduction
3
de-intercalation into/out of graphite from non-aqueous room temperature electrolytes
comprising lithium salts such as LiF dissolved in organic solvents such as ethylene
carbonate had already been well documented in 1990. In fact, this is the basis of
graphite anode operation in modern Li-ion batteries [16, 17]. Under this condition,
graphite shows an outstanding cycle life, exceeding thousands of cycles, often with
no structural disintegration.
Further discoveries reported from University of Cambridge by myself during
2010–2016 indicated that molten LiCl can be hydrolyzed to produce HCl, and the HCl
formed can dissolve into the molten salt to create hydrogen cations. The discharge
of hydrogen cations on the cathode produces hydrogen at elevated temperatures. The
hydrogen produced can be considered either as fuel, as reductant to reduce metal
oxides to corresponding metals [18] or as an efficient exfoliating gas causing the
exfoliation of the graphite electrode into high-quality graphene nanosheets [19–21].
The graphene product was evaluated for a number of applications, including supercapacitors [22], lithium-ion batteries [23], high-performance ceramic composites [24]
and water purification [25].
These series of discoveries were interesting; since graphene is a relatively new
member of carbon family with a wide range of interesting properties and applications.
The other valuable member of the carbon family is diamond, the hardest and the most
thermally conductive material ever known. In 2015, I proposed a molten salt route
for producing diamond nanocrystals in molten LiCl, at far less severe conditions than
conventional processes [26].
In the above-mentioned studies, carbonaceous solid materials exposed to the
molten salts are used as the carbon source. The source of carbon used in molten
salt processes can also be carbon dioxide (CO 2 ) which is considered to be the main
greenhouse gas. Capture of CO 2 and its conversion to useful carbon materials for
various applications, therefore, is an interesting approach to tackle CO 2 emission
challenges. Carbon dioxide can be captured in a single molten salt or often a mixture
of molten salts to form amorphous carbon, CNTs [27] and even nanodiamonds [28].
The accumulation of non-biodegradable plastic wastes in the earth’s environment is
another emerging global problem. The molten salt conversion of plastic wastes into
nanostructured carbon provides a solution for this crisis [29]. This book summarizes
these findings.
References
1. F.M. Perkin, The discovery of the alkalai metals by Humphry Davy: The bearing of the discovery
upon industry. Trans. Faraday Soc. 3, 205–219 (1908)
2. R. Bunsen, Darstellung des Magnesiums auf electrolutischem, Ann. d. Chem. 82, 137 (1852)
3. R. Lumle (ed.), Fundamentals of Aluminium Metallurgy, Processing and Application and
Production (Woodhead Publishing, Sawston, UK, 2011)
4. M.W. Rosenthal, P.R. Kasten, R.B. Briggs, Molten-Salt Reactors—history status, and potential.
Nucl. Appl. Technol. 8, 107–117 (1970)
5. J. Uhlir, Chemistry and technology of Molten Salt Reactors—history and perspectives. J. Nucl.
Mater. 360, 6–11 (2007)
3
de-intercalation into/out of graphite from non-aqueous room temperature electrolytes
comprising lithium salts such as LiF dissolved in organic solvents such as ethylene
carbonate had already been well documented in 1990. In fact, this is the basis of
graphite anode operation in modern Li-ion batteries [16, 17]. Under this condition,
graphite shows an outstanding cycle life, exceeding thousands of cycles, often with
no structural disintegration.
Further discoveries reported from University of Cambridge by myself during
2010–2016 indicated that molten LiCl can be hydrolyzed to produce HCl, and the HCl
formed can dissolve into the molten salt to create hydrogen cations. The discharge
of hydrogen cations on the cathode produces hydrogen at elevated temperatures. The
hydrogen produced can be considered either as fuel, as reductant to reduce metal
oxides to corresponding metals [18] or as an efficient exfoliating gas causing the
exfoliation of the graphite electrode into high-quality graphene nanosheets [19–21].
The graphene product was evaluated for a number of applications, including supercapacitors [22], lithium-ion batteries [23], high-performance ceramic composites [24]
and water purification [25].
These series of discoveries were interesting; since graphene is a relatively new
member of carbon family with a wide range of interesting properties and applications.
The other valuable member of the carbon family is diamond, the hardest and the most
thermally conductive material ever known. In 2015, I proposed a molten salt route
for producing diamond nanocrystals in molten LiCl, at far less severe conditions than
conventional processes [26].
In the above-mentioned studies, carbonaceous solid materials exposed to the
molten salts are used as the carbon source. The source of carbon used in molten
salt processes can also be carbon dioxide (CO 2 ) which is considered to be the main
greenhouse gas. Capture of CO 2 and its conversion to useful carbon materials for
various applications, therefore, is an interesting approach to tackle CO 2 emission
challenges. Carbon dioxide can be captured in a single molten salt or often a mixture
of molten salts to form amorphous carbon, CNTs [27] and even nanodiamonds [28].
The accumulation of non-biodegradable plastic wastes in the earth’s environment is
another emerging global problem. The molten salt conversion of plastic wastes into
nanostructured carbon provides a solution for this crisis [29]. This book summarizes
these findings.
References
1. F.M. Perkin, The discovery of the alkalai metals by Humphry Davy: The bearing of the discovery
upon industry. Trans. Faraday Soc. 3, 205–219 (1908)
2. R. Bunsen, Darstellung des Magnesiums auf electrolutischem, Ann. d. Chem. 82, 137 (1852)
3. R. Lumle (ed.), Fundamentals of Aluminium Metallurgy, Processing and Application and
Production (Woodhead Publishing, Sawston, UK, 2011)
4. M.W. Rosenthal, P.R. Kasten, R.B. Briggs, Molten-Salt Reactors—history status, and potential.
Nucl. Appl. Technol. 8, 107–117 (1970)
5. J. Uhlir, Chemistry and technology of Molten Salt Reactors—history and perspectives. J. Nucl.
Mater. 360, 6–11 (2007)