There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

There is a special reason for reviewing this book at this time: it is the 50th edition of a compendium that is known and used frequently in most chemical and physical laboratories in many parts of the world. Surely, a publication that has been published for 56 years, withstanding the vagaries of science in this century, must have had something to offer. There is another reason: while the book is a standard fixture in most chemical and physical laboratories, including those in medical centers, it is not as frequently seen in the laboratories of physician's offices (those either in solo or group practice). I believe that the Handbook can be useful in those laboratories. One of the reasons, among others, is that the various basic items of information it offers may be helpful in new tests, either physical or chemical, which are continuously being published. The basic information may relate

Handbook of Chemistry and Physics

An aluminium-ion battery is reported that can charge within one minute, and offers improved cycle life compared to previous devices; it operates through the electrochemical deposition and dissolution of aluminium at the anode, and the intercalation/de-intercalation of chloroaluminate anions into a novel graphitic-foam cathode. The low cost and useful electrical properties of aluminium suggest that rechargeable Al-ion batteries could offer viable and safe battery technology, but problems with cathode materials, poor cycling performance and other complications have persisted. Here Hongjie Dai and colleagues describe an Al-ion battery that can charge within one minute and offers substantially improved cycle life with little decay in capacity compared to previous devices reported in the literature. The battery operates through the electrochemical deposition and dissolution of Al and intercalation/de-intercalation of chloroaluminate anions into a novel 3D graphitic foam cathode using a non-flammable ionic liquid electrolyte. The development of new rechargeable battery systems could fuel various energy applications, from personal electronics to grid storage1,2. Rechargeable aluminium-based batteries offer the possibilities of low cost and low flammability, together with three-electron-redox properties leading to high capacity3. However, research efforts over the past 30 years have encountered numerous problems, such as cathode material disintegration4, low cell discharge voltage (about 0.55 volts; ref. 5), capacitive behaviour without discharge voltage plateaus (1.1–0.2 volts6 or 1.8–0.8 volts7) and insufficient cycle life (less than 100 cycles) with rapid capacity decay (by 26–85 per cent over 100 cycles)4,5,6,7. Here we present a rechargeable aluminium battery with high-rate capability that uses an aluminium metal anode and a three-dimensional graphitic-foam cathode. The battery operates through the electrochemical deposition and dissolution of aluminium at the anode, and intercalation/de-intercalation of chloroaluminate anions in the graphite, using a non-flammable ionic liquid electrolyte. The cell exhibits well-defined discharge voltage plateaus near 2 volts, a specific capacity of about 70 mA h g–1 and a Coulombic efficiency of approximately 98 per cent. The cathode was found to enable fast anion diffusion and intercalation, affording charging times of around one minute with a current density of ~4,000 mA g–1 (equivalent to ~3,000 W kg–1), and to withstand more than 7,500 cycles without capacity decay.

An ultrafast rechargeable aluminium-ion battery

Quest for Nonaqueous Multivalent Secondary Batteries: Magnesium and Beyond

We have investigated the reaction mechanism of the electrochemical reduction of carbon dioxide to hydrocarbons on copper electrodes. This reaction occurs via two pathways: a C1 pathway leading to methane, and a C2 pathway leading to ethylene. To identify possible intermediates in the reduction of carbon dioxide we have studied the reduction of small C1 and C2 organic molecules containing oxygen. We followed the formation and consumption of intermediates during the reaction as a function of potential, using online mass spectrometry. For the C1 pathway we show that it is very likely that CHOads is the key intermediate towards the breaking of the C–O bond and, therefore, the formation of methane. For the C2 pathway we suggest that the first step is the formation of a CO dimer, followed by the formation of a surface-bonded enediol or enediolate, or the formation of an oxametallacycle. Both the enediol(ate) and the oxametallacycle would explain the selectivity of the C2 pathway towards ethylene. This new mechanism is significantly different from existing mechanisms but it is the most consistent with the available experimental data.

A new mechanism for the selectivity to C1 and C2 species in the electrochemical reduction of carbon dioxide on copper electrodes

The electrodeposition and surface morphology of aluminium on tungsten (W) and aluminium (Al) electrodes from 2 : 1 molar ratio AlCl 3 –[EMIm]Cl ionic liquids were investigated. Analyses of the chronoamperograms indicate that the deposition process of aluminium on W substrates was controlled by instantaneous nucleation with diffusion-controlled growth, while the deposition processes of aluminium on Al electrodes were found to be associated with kinetic limitations. Constant potential deposition experiments showed that the electrodeposits obtained on both W and Al electrodes between − 0.10 and − 0.40 V (vs. Al(III)/Al) are dense, continuous and well adherent. Dense aluminium deposits were also obtained on Al substrates using constant current deposition between 10 and 70 mA/cm 2 , and the current efficiency was found to be dependent of the current density varying from 85% to 100%.

Electrodeposition of aluminium from ionic liquids: Part I—electrodeposition and surface morphology of aluminium from aluminium chloride (AlCl3)–1-ethyl-3-methylimidazolium chloride ([EMIm]Cl) ionic liquids

This work presents the studies of the nucleation processes and surface morphology of aluminium electrodeposits obtained on tungsten (W) and aluminium (Al) electrodes from 2 : 1 molar ratio aluminium chloride (AlCl3)–trimethylphenylammonium chloride (TMPAC) ionic liquids. The deposition processes of aluminium on both W and Al substrates were controlled by an instantaneous nucleation with diffusion-controlled growth. The number densities of the nuclei involved were estimated from the chronoamperometric measurements. On W electrodes, the bulk deposition of aluminium was preceded by an underpotential deposition (UPD) of ca. 2 / 3 monolayer of aluminium. Dense aluminium electrodeposits were obtained on both W and Al substrates at potentials between − 0.10 and − 0.40 V vs. Al(III)/Al.

Electrodeposition of aluminium from ionic liquids: Part II - studies on the electrodeposition of aluminum from aluminum chloride (AICl3) - trimethylphenylammonium chloride (TMPAC) ionic liquids

Oxygen reduction and hydrogen evolution–oxidation reactions on Cu(hkl) surfaces

This paper presents a study of the aluminum deposition processes in dimethylsulfone (DMSO2)-based electrolytes. The electrical conductivities of the AlCl3/DMSO2 electrolytes were investigated as a function of temperature (70–180 °C) and molar ratio of AlCl3 to DMSO2 (from 0.1:1 to 0.8:1). The results show that the temperature-dependent conductivities of the electrolytes fit well with the Vogel–Tamman–Fulcher (VTF) equation. The optimum operating conditions for the electrodeposition of aluminum from AlCl3/DMSO2 electrolytes were determined based on the studies of the effects of current density, electrolyte temperature and the molar ratio of AlCl3 to DMSO2 on the quality of the deposited coatings. Dense, bright and adherent aluminum coatings were obtained in AlCl3/DMSO2 electrolytes over a wide range of temperatures (110–150 °C) and current densities (5 to 20 A dm− 2). The preliminary results from Al refining experiments showed that Al alloy can be purified via electrolysis in 0.2:1 AlCl3/DMSO2 at 130 °C with a current density of 10 A dm− 2.

Gessie Brisard

Papers

Electrodeposition of aluminium from ionic liquids: Part I—electrodeposition and surface morphology of aluminium from aluminium chloride (AlCl3)–1-ethyl-3-methylimidazolium chloride ([EMIm]Cl) ionic liquids

Electrodeposition of aluminium from ionic liquids: Part II - studies on the electrodeposition of aluminum from aluminum chloride (AICl3) - trimethylphenylammonium chloride (TMPAC) ionic liquids

Oxygen reduction and hydrogen evolution–oxidation reactions on Cu(hkl) surfaces

Studies on the AlCl3/dimethylsulfone (DMSO2) electrolytes for the aluminum deposition processes

Influence of adsorption processes on the CO2 electroreduction: An electrochemical mass spectrometry study