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

Abstract

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.

A Computational Study of a Single‐Walled Carbon‐Nanotube‐Based Ultrafast High‐Capacity Aluminum Battery

“…The capacity calculated for each tube is listed in Ta ble 1. [68] The storage capacities obtainedf or the reported SWNTsa re higher than that of the earlier studied graphite cathode( 70 mA hg À1 ), [27][28][29] whichs uggests the application of SWNTsa ss uperior cathode host for Al batteries. For the (10,10) SWNT,t he calculated capacity is 223 mA hg À1 ,w hich furtheri ncreases to 236 to 251 mA hg À1 for the (15,15) and (20,20) SWNT,r espectively,a nd as pecific capacity as high as 275 mA hg À1 can be obtained with the (25,25) SWNT.T he systematici ncrease in capacity as the tube diameter increases is in accord with earlier studies on Li-ion batteries with SWNT electrodes.…”

“…[17,18,[20][21][22][23]26] An Al battery that is comprised of three-dimensional graphitic-foamc athode graphite has attracted globala ttention owing to its ultrafast charging rate and the involvement of intercalation/deintercalation of AlCl 4 anions during charging/discharging, respectively. [29][30][31][32] However,m any experimental studies on anion intercalation and the theoretical study we conducted on graphite electrodeh ave shown that the very first intercalation step (cycle) differs from the other successive steps because it involves the activation of partially closed interlayer spaceso f graphite layers during the initial intercalation of the anion, which results in lower discharge capacities. [29][30][31][32] However,m any experimental studies on anion intercalation and the theoretical study we conducted on graphite electrodeh ave shown that the very first intercalation step (cycle) differs from the other successive steps because it involves the activation of partially closed interlayer spaceso f graphite layers during the initial intercalation of the anion, which results in lower discharge capacities.…”

Graphene: A Cathode Material of Choice for Aluminum‐Ion Batteries

“…Thes plitting and merging of the G-band of graphene in the Raman spectra confirm reversible AlCl 4 À1 anion intercalation and deintercalation in graphene layers during charging and discharging, respectively ( Figure 2g). [44] Chen et al again utilized the same high temperature processing technique to obtain defect-free graphene in powder form. It is realized that defects are not only inactive sites but also act as obstacles for AlCl 4 À1 anion percolation.…”

“…It resulted in very stable and higher discharge capacity of 123 mAh g À1 over 10 4 cycles at current rate of 5Ag À1 with Coulombic efficiencyo fg reater than 98 % ( Figure 2b). [44] Although natural graphite can reversibly host AlCl 4 À1 anions,i ts hows poor rate capability than fewlayer graphene.Aspecific capacity of only 60 mAh g À1 could be attained at comparatively low current rate of 0.66 Ag À1 .It is shown to be true for pyrolytic graphite as well, which exhibits ac apacity of only 20 mAh g À1 at ac urrent rate of 0.264 Ag À1 . Zhang et al clearly demonstrated enhanced kinetics of AlCl 4 À1 anions in graphene cathodes with reduced crystallite size along c-axis.…”

An aluminium battery operating with an aqueous electrolyte

“…This communication reports on the construction and testing of a fully functional aqueous Al-ion cell. It should be noted that the majority of Al-ion research focusses on room temperature ionic liquid electrolyte systems (RTILs) theoretically allowing the utilisation of aluminium metals high capacity through reversible deposition [3][4][5][6][7][8][9][10]. The primary research aim becomes the identification of positive electrode materials that will not severely limit cell capacity.…”