Self‐Assembled Surfactant‐Polyoxovanadate Soft Materials as Tuneable Vanadium Oxide Cathode Precursors for Lithium‐Ion Batteries

Abstract

The mixing of [V 10 O 28 ] 6À decavanadate anions with a dicationic gemini surfactant (gem) leads to the spontaneous self-assembly of surfactant-templated nanostructured arrays of decavanadate clusters. Calcination of the material under air yields highly crystalline, sponge-like V 2 O 5 (gem-V 2 O 5 ). In contrast, calcination of the amorphous tetrabutylammonium decavanadate allows isolation of a more agglomerated V 2 O 5 consisting of very small crystallites (TBA-V 2 O 5 ). Electrochemical analysis of the materials' performance as lithium-ion intercalation electrodes highlights the role of morphology in cathode performance. The large crystallites and long-range microstructure of the gem-V 2 O 5 cathode deliver higher initial capacity and superior capacity retention than TBA-V 2 O 5 . The smaller crystallite size and higher surface area of TBA-V 2 O 5 allow faster lithium insertion and superior rate performance to gem-V 2 O 5 .

Synthesis, characterization and properties of indium-doped manganese oxide molecular sieve sponges

“…Inorganic sponges also have numerous applications, for instance, the oxidative coupling of methane by a TiO 2 –Mn 2 O 3 –Na 2 WO 4 -foam catalyst, 15 efficient urea oxidation in a direct urea fuel cell by a FeNi-supported carbon sponge, 16 construction of lithium-ion batteries using a V 2 O 5 sponge, 17 photocatalytic degradation of high concentration dyes by a Sn 4+ -doped ZnO sponge, 18 and fabrication of an asymmetric supercapacitor using a MnCo-MOF–modified graphene sponge. 19 Some sponges/foams are usually prepared via a conventional ceramic route with high-temperature calcinations; however, this route is unsuitable for fabricating manganese oxide sponges because most manganese oxides exhibit metastable phases due to oxygen loss at high temperatures.…”

A mass-producible polyoxovanadate cathode for ultrafast-kinetics zinc-ion batteries

“…In marked contrast to conventional layered metal oxides, polyoxometalates (POMs) show unique multi-directionally interconnected migration channels formed by the discrete but ordered three-dimensional (3D) arrangement of plentiful anionic polynuclear metal-oxo clusters. The distinctive structural attribute endows POMs with substantial potential for applications in lithium-ion batteries (LIBs), [33][34][35] sodium-ion batteries (NIBs), 36 and redox flow batteries. However, there is still limited research on their implementation in ZIBs.…”