Stable CoSe₂/carbon nanodice@reduced graphene oxide composites for high-performance rechargeable aluminum-ion batteries

Abstract

A rechargeable aluminum-ion battery exhibits outstanding perofrmance due to the rationally designed CoSe2-based cathode material.

Porous α‐MnSe Microsphere Cathode Material for High‐Performance Aluminum Batteries

“…From Figure a, the positions of diffraction peaks have scarcely changed, implying the nearly invariable interplanar spacing of α‐MnSe cathode. Hence guest ions in the insertion to the α‐MnSe cathode should be aluminum ions instead of chloroaluminate anions since the intercalation of large‐sized chloroaluminate anions (5.3 Å) would lead to an obvious variation of the crystal structure …”

The Rechargeable Aluminum Battery: Opportunities and Challenges

“…[114] It was reported that electrophilic elements from Group VI Aand the nucleophilic C2 carbon in the imidazole ring can react with each other, [115] and this cannot be avoided in most Al-S batteries.Another potential side reaction is the reduction of the electrolyte on the cathode surface.E ven though the electrolyte has astable electrochemical window as low as 0V (vs.A l/AlCl 4 À )o naglassy carbon working electrode, [116] it is not certain that the reduction voltage of the electrolyte remains at 0V during discharge on various cathodes because such transition-metal oxide/sulfide cathodes always have catalytic activity to some extent, [117][118][119] and this can narrow the electrochemical window of the electrolyte. Up to now,there is no direct evidence of such catalytic activity of cathodes for electrolyte reduction, however, several studies have shown an "excess capacity" phenomenon [47,86] which might be caused by reduction of the electrolyte because the cut-off discharge voltage is always below 0.1 V.…”

“…[91,92] To reduce this kinetic obstacle,t wo strategies have been used: 1) nanometer transition-metal sulfides (particles,f ibers,o r layers) have been used instead of micrometer ones to increase the surface area and offer more solid diffusion pathways;2 )transition-metal sulfide composites with carbon materials composed of carbon nanotubes (CNTs) or graphene to improve the electrical conductivity and electrolyte wettability.U sing these strategies,t he discharge current density of aC o 9 S 8 @CNT-CNF (CNF = carbon nanofiber) cathode can reach 1Ag À1 with ac apacity of approximately 100 mAh g À1 . [87] However,a sw ith transition-metal oxides,m ost transition-metal sulfides/selenides also suffer fast capacity fade,e specially during the first few cycles.U sing CoSe 2 , [86] it was found that an amorphous layer formed during cycling was the prime culprit leading to capacity fade.…”

Novel Ni–Fe‐Layered Double Hydroxide Microspheres with Reduced Graphene Oxide for Rechargeable Aluminum Batteries

“…After NiFe–LDH got positive charges from the poly(diallyl dimethylammonium chloride (PDDA) solution and the negatively‐charged rGO was incorporated, rGO films homogenously wrapped around the NiFe–LDH microspheres. This phenomenon demonstrates the successful synthesis strategy based on electrostatic self‐assembly . The transmission electron microscopy (TEM) image (Figure S2, Supporting Information) shows the single hexagonal nanosheet of NiFe–LDH with a side length of about 500 nm.…”

“…The intercalation of chloroaluminate anions would cause severe volume expansion and the limited capacity of electrodes because of the large size of chloroaluminate anions (5.3 Å). Hence, high‐capacity cathode based on the intercalation of small‐sized aluminum ions (0.39 Å), such as Ni 3 S 2 , CoSe 2 , and Co 3 S 4 , was thoroughly investigated. However, the high charge density of Al 3+ would contribute to strong electrostatic interaction with the host materials, which results in slow diffusion kinetics and structural collapse .…”