Preparation of Hydrophobic PPy Coated V₂O₅ Yolk–Shell Nanospheres-Based Cathode Materials with Excellent Cycling Performance

Abstract

Vanadium pentoxide (V 2 O 5 ) has been extensively used as the cathode material for lithium-ion batteries (LIBs). But the chemical dissolution of V 2 O 5 in the electrolyte greatly restrains its electrochemical performance, especially cycling stability. In the present research, polypyrrole (PPy)-coated V 2 O 5 yolk−shell nanospheres (V 2 O 5 @PPy) were synthesized by a simple solvothermal method in combination with the vapor deposition method. The density functional theory (DFT) analysis demonstrated that the PPy layer formed by oxidative polymerization manifested hydrophobicity and shielded the trace amount of water on electrode materials. Moreover, the polymerization process induced a gradient distribution of oxygen vacancies in the material and facilitated the rapid transfer of charges. The yolk−shell structure provided sufficient spaces to alleviate the structure change of electrode materials during lithiation/delithiation and inhibited the structural degradation. Hence, V 2 O 5 @PPy displayed an excellent cycling performance by improving the electrical conductivity and suppressing the chemical dissolution of V 2 O 5 . When the discharge current densities were 1 A g −1 and 5 A g −1 , an ultralong cycling life of 1000 cycles (discharge specific capacity of 133.3 mAh g −1 ) and 5000 cycles (discharge specific capacity of 121 mAh g −1 ) was obtained in the voltage range of 2.5−4.0 V, respectively.

Light‐responsive bilayered hydrogel for freshwater production from surface soil moisture

“…However, according to previous literature reported, more AA would reduce the thermo‐responsiveness of NIPAM 41 . After the introduction of the PPy into the top layer of PNA, the swelling ratio of composite hydrogel (LRBH) was at least 50% lower than that of PNA (Figure 1C), which can be attributed to the hydrophobicity of PPy 42 . Therefore, to ensure that LRBH had enough photothermal materials without reducing the water absorption performance of LRBH, a water purification system with a bilayer structure was designed.…”

Intrinsically conducting polymers and their combinations with redox-active molecules for rechargeable battery electrodes: an update

“…A coating with PPy of V 2 O 5 suggested as positive electrode material in nonaqueous lithium-ion batteries served the same purpose, up to 5000 cycles were recorded (Liang et al 2020). Core-shell nanobelts of V 2 O 5 coated with PEDOT have shown remarkable lithium storage capability and even at high rate (10 C) no capacity loss after 500 cycles (Ren et al 2020a).…”

Rational Construction of ZnCo-ZIF-Derived ZnS@CoS@NiV-LDH/NF Binder-Free Electrodes Via Core–Shell Design for Supercapacitor Applications with Enhanced Rate Capability

“…Among the many transition metal hydroxides, nickel-based LDH has been regarded as a very ideal electrode material because of its abundant content, high capacitance value, and excellent chemical stability. Vanadium has a variety of oxidation states, abundant resources and low price, and is often used as an electrode material . Apparently, when vanadium is introduced into NiV-LDH of nickel-based LDH, the synergistic effect of the two metal ions of Ni and V will show good electrochemical performance .…”