Leaf‐Like V₂O₅ Nanosheets Fabricated by a Facile Green Approach as High Energy Cathode Material for Lithium‐Ion Batteries

Abstract

Lithium-ion batteries (LIBs) have attracted considerable attention due to their wide applications, such as in portable electronic devices, implantable medical devices, and electric vehicles (EVs). [ 1 ] To meet the constantly increasing demands of upcoming electronic devices, new LIBs require substantial improvements in energy capacity, cycling stability, and rate capability of both the cathode and anode materials. [ 2,3 ] Among cathode materials for LIBs, orthorhombic vanadium pentoxide (V 2 O 5 ) the most stable form in the vanadium oxide family, has gained great interest due to its high energy density, low cost, abundant sources, and good safety properties. [4][5][6][7] The theoretical capacity of V 2 O 5 with two Li intercalations/ deintercalations is about 294 mA h g − 1 , much higher than those of more commonly used cathode materials, making it a very promising cathode material for next-generation LIBs. However, the practical use of V 2 O 5 as cathode materials for LIBs has been hampered due to its poor cycling stability, low electronic and ionic conductivity, and slow electrochemical kinetics. [8][9][10] To overcome these problems, decreasing their particle size to nanoscale level is generally believed to be one of the most effective approaches due to the shorter transport lengths for both electrons and Li ions, larger electrode/electrolyte contact area, and better accommodation of the strain of Li intercalation/deintercalation in nanomaterials. [ 11 , 12 ] The unique performance of nanomaterials lies in their large specifi c surface and favorable structural properties. 2D nanosheets often possess large exposed surfaces and specifi c facets, which make them more attractive in energy conversion devices. [ 13 ] 2D structures are ideal frameworks for fast Li storage, which requires stability, large active surface area, and short transport path for Li intercalation/deintercalation. [ 14 ] There have been many researches on nanostructured V 2 O 5 materials for LIBs. [ 4-7 , 15-20 ] However, there are few reports on 2D nanostructured V 2 O 5 for LIBs. The only report on 2D nanostructured V 2 O 5 was that Zhang's group prepared large-area pure V 2 O 5 nanosheets by dissolution-splitting method from their parent bulk cyrstal using ammonium persulfate as intercalated compound. [ 21 ] The method is a typical top-down method. The as-prepared product exhibits enhanced lithium storage properties including high reversible capacity, good cycling, and rate performance.In this communication, we demonstrate a novel and facile green method to prepare 2D leaf-like V 2 O 5 nanosheets as illustrated in Figure 1 . V 2 O 5 powders were reacted with H 2 O 2 in combination with ultrasonic treatment to generate V 2 O 5 gel. Then the V 2 O 5 gel was diluted, freeze-dried, and further treated at 450 ° C in air to obtain V 2 O 5 nanosheets. Used as cathode material for LIBs, this 2D leaf-like V 2 O 5 nanosheets exhibits excellent Li storage properties, including high reversible capacity, high rate capability, and good capacity reten...

Vanadium-based nanostructure materials for secondary lithium battery applications

“…11 The with a slight capacity fading. In recent years, 2D materials, including nanosheets 24,25 and entanglement networks of nanobelts, 26,27 Fig. 2a.…”

Electrodeposition of Vanadium Oxides at Room Temperature as Cathodes in Lithium-Ion Batteries

“…A great number of strategies have been proposed to develop nanoelectrodes including the self-assembled nanostructures [4], hierarchical 3D mixed conducting networks [5], self-supported nanoarrays with diverse morphologies on 2D/3D conductive substrates as binder-free electrodes [6], 2D nanostructures through dissolution-splitting method from their bulk crystal [7], ultrasonic treatment of powders [8], nanocomposites composed of graphene or carbon with actives [9][10][11], introduction of surface defects by gas annealing [12], and doping by metallic species [13,14]. Nevertheless, in some cases, the nanostructured electrodes require complicated fabrication approaches and present poor mechanical stability along with limited rate capability.…”

Rational Construction of a Functionalized V2O5 Nanosphere/MWCNT Layer‐by‐Layer Nanoarchitecture as Cathode for Enhanced Performance of Lithium‐Ion Batteries

“…[9][10][11][12][13] Moreover, cost effectiveness, facility of synthesis, and abundance in natural resource are other important advantages of investigatingV 2 O 5 cathode.Nevertheless, achieving decent electrochemical performances for V 2 O 5 in various aspects, including specifi c capacity, rate capability, and cycle life, has been a challenge which is ascribed to its low ionic diffusivity and inferior electrical conductivity. [ 9,[14][15][16] To address these intrinsic drawbacks, an effective strategy was adopted to decrease the active materials to nanoscale level, such as nanowires, [ 17 ] nanorods, [ 18 ] nanobelts, [ 19 ] and nanospheres, [ 20,21 ] which can shorten the transport lengths both for electrons and Li ions, minimize the effect of the low ionic diffusivity, and better accommodate the strain of Li ions intercalation/deintercalation in active materials.…”