A rechargeable 6-electron Al–Se battery with high energy density

Multivalent cationic and anionic mixed redox of an Sb2S3 cathode toward high-capacity aluminum ion batteries

“…S3a†). 11,12 Furthermore, on the charging curve at this current density, a third-stage charging plateau appeared in the voltage range 1.8–2.0 V, which can be judged to be the oxidation of S (S 0 → S x + ). 11 However, no corresponding high-potential discharge plateau was observed on the discharge curve, which resulted in a low coulombic efficiency (∼95%).…”

Metal–Organic Framework Structure with Fe–Co–Se (MIL-88A/Fe–Co@Se) as a Cathode for Aluminum Batteries

“…However, similar to the reversible transformation of elemental Fe, there is also a part of Se 2 2+ that is not converted to Se 2 2– in the reduction reaction. Considering the characteristics of Se, which is more prone to dissolution/deposition side reactions, the amount of the irreversible reaction of Se may be more than that of Fe. ,, In order to further study the redox process of FeSe 2 during charging and discharging, ex situ XRD tests were performed on cathode materials at different voltages, and the results are shown in Figure S4. From the pattern, it can be seen that the pristine electrode sample before charging/discharging and the sample charged to 1.9 V have two main peaks of FeSe 2 at about 35°.…”

“…We propose that selenium can be compounded with MOFs to form MOF@Se hybrids, which have both the unique structure of the MOF and the high capacity of selenium. 39,40 Therefore, these hybrids as cathode materials will bring better cycling stability and higher capacity. In our work, MIL-88A@Fe−Co hydroxide yolk−shell nanotubes (YSNTs) were used as Se loading materials for the first time, 41 and the Fe element in YSNTs was used to generate FeSe 2 with Se, while the original structure of the nanorods was maintained as an aggregate.…”

“…For example, as important materials for Li–S batteries, they suppress the “shuttle effect” of polysulfides generated in the reaction and inhibit lithium dendrite formation, as support structures for cathode materials in Al–organic batteries to reduce solubility in the electrolyte, , and also as composite active materials on the unique structure of MOFs as cathode materials to directly improve the electrochemical performance, such as MIL-53 (Fe) and Ni-BTC MOF in Li-ion batteries. ,, Overall, these cases support the view that MOFs have many uses, and the rational and flexible use of MOFs can help relevant research to be improved. We propose that selenium can be compounded with MOFs to form MOF@Se hybrids, which have both the unique structure of the MOF and the high capacity of selenium. , Therefore, these hybrids as cathode materials will bring better cycling stability and higher capacity. In our work, MIL-88A@Fe–Co hydroxide yolk–shell nanotubes (YSNTs) were used as Se loading materials for the first time, and the Fe element in YSNTs was used to generate FeSe 2 with Se, while the original structure of the nanorods was maintained as an aggregate. , This resulted in enhanced reversibility of intercalation/deintercalation in charging/discharging and significantly improved the cycling stability of the battery with Se as the cathode material.…”

Graphene-encapsulated selenium@polyaniline nanowires with three-dimensional hierarchical architecture for high-capacity aluminum–selenium batteries

“…In contrast, selenium (Se), as one of the typical conversion-type positive materials, has attracted great attention due to its competitive high theoretical specic capacity based on 4-electron transfer (1357 mA h g À1 ), or even 6-electron transfer (2036 mA h g À1 ), high discharge voltage platform ($1.8 V) and improved electrical conductivity ($1 Â 10 À3 S m À1 ) in comparison with the widely developed sulfur positive electrode. [12][13][14] Therefore, Se has potential applications in volume-constrained elds such as miniaturization and high-power density demands.…”