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

The rechargeable aluminum-ion battery

A critical overview of the latest developments in the aluminum battery technologies is reported. The substitution of lithium with alternative metal anodes characterized by lower cost and higher abundance is nowadays one of the most widely explored paths to reduce the cost of electrochemical storage systems and enable long-term sustainability. Aluminum based secondary batteries could be a viable alternative to the present Li-ion technology because of their high volumetric capacity (8040 mAh cm(-3) for Al vs 2046 mAh cm(-3) for Li). Additionally, the low cost aluminum makes these batteries appealing for large-scale electrical energy storage. Here, we describe the evolution of the various aluminum systems, starting from those based on aqueous electrolytes to, in more details, those based on non-aqueous electrolytes. Particular attention has been dedicated to the latest development of electrolytic media characterized by low reactivity towards other cell components. The attention is then focused on electrode materials enabling the reversible aluminum intercalation-deintercalation process. Finally, we touch on the topic of high-capacity aluminum-sulfur batteries, attempting to forecast their chances to reach the status of practical energy storage systems.

An Overview and Future Perspectives of Aluminum Batteries

Recently, interest in aluminium ion batteries with aluminium anodes, graphite cathodes and ionic liquid electrolytes has increased; however, much remains to be done to increase the cathode capacity and to understand details of the anion–graphite intercalation mechanism. Here, an aluminium ion battery cell made using pristine natural graphite flakes achieves a specific capacity of ∼110 mAh g−1 with Coulombic efficiency ∼98%, at a current density of 99 mA g−1 (0.9 C) with clear discharge voltage plateaus (2.25–2.0 V and 1.9–1.5 V). The cell has a capacity of 60 mAh g−1 at 6 C, over 6,000 cycles with Coulombic efficiency ∼ 99%. Raman spectroscopy shows two different intercalation processes involving chloroaluminate anions at the two discharging plateaus, while C–Cl bonding on the surface, or edges of natural graphite, is found using X-ray absorption spectroscopy. Finally, theoretical calculations are employed to investigate the intercalation behaviour of choloraluminate anions in the graphite electrode. Rechargeable aluminium ion batteries are an emerging class of energy storage device. Here the authors reveal high-quality natural graphite as a promising cathode for Al-ion batteries, also identifying chloroaluminate anion intercalation in graphite by Raman spectroscopy.

Advanced rechargeable aluminium ion battery with a high-quality natural graphite cathode

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

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.

G. Dubé

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

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