CuO Necklace: Controlled Synthesis of a Metal Oxide and Carbon Nanotube Heterostructure for Enhanced Lithium Storage Performance

Abstract

Metal oxide and nanocarbon heterostructures provide a powerful strategy to materials innovation because judicious combination of different materials may afford collective properties that are otherwise unattainable. However, design and fabrication of spatially patterned heterostructures has been still challenging. Here, we develop a facile approach to synthesize a CuO and carbon nanotube necklace-like heterostructure in solution for enhanced lithium storage performance. Observations confirm that propagative sidewall alkylcarboxylation of carbon nanotubes in liquid ammonia allows the CuO nanospheres to grow on the functional defect sites introduced by the functionalization. Such a method does not require surfactants and is highly scalable. The resulting materials show high lithium ion storage capacities (stable at 500 mAh g −1 ) and enhanced cycling performance as a lithium-ion battery anode. The improved performance is attributed to the necklace-like nanostructure, which provides an electrical channel as well as excess room to accommodate the volume changes of CuO during electrochemical cycling.

Single-walled carbon nanotubes templated CuO networks for gas sensing

“…24 Firstly, 1 ml of oxidized SWCNTs (P3, Carbon Solution Inc.) in NaOH aqueous solution (0.05 mg/ml) with the pH of 11 was added into a mixture composed of 40 μL CuCl 2 aqueous solution (0.1 M) and 2 mL NH 3 ·H 2 O (14%-15%). The system was incubated at 70 °C for 1.5 hours.…”

Carbonate-assisted hydrothermal synthesis of porous, hierarchical CuO microspheres and CuO/GO for high-performance lithium-ion battery anodes

“…23,[26][27][28]39 During subsequent cycles (2nd, third and fifth), all cathodic and anodic peaks of bare CuO MSs and CuO/GO electrodes are reproductive, indicating high reversibility for the redox reaction. Fig.…”

“…The irreversible capacity loss mainly result from the formation of SEI layer, interfacial lithium storage and electrolyte decomposition. 23,40 8a displays the cycling performances of the two CuO electrodes with a current density of 0.5 C for 500 cycles. The CuO/GO hybrid electrode demonstrates much better cycling performance than that of the bare CuO electrode.…”

“…This performance is remarkable compared with many works reported previously. [21][22][23][25][26] It is worth noting that the capacity of CuO/GO hybrid electrode gradually decreases to 573 mAh g -1 in the first 40 cycles owing to the irreversible processes, such as interfacial lithium storage, the formation of SEI layer and the electrolyte decomposition; then capacity slowly increases to 691.0 mAh g -1 after 170 cycles which may result from the activation of the porous CuO MSs, because the interiors of the porous CuO MSs are probably not in good contact with the electrolyte and the formation of the SEI layer may need a number of cycles. 39,41 As the cycle number continues to increase, the reversible capacity maintains stable till 350 cycles and slowly decreases to 500 mAh g -1 after 500 cycles.…”

“…Therefore, there is another effective way to fabricate promising anode materials for LIBs by introducing a highly conductive layer. It is worth noting that attempts have also been made to improve the performance of CuO-based electrodes by coating with carbon or polymer materials, such as carbon nanotube [23][24][25] , graphene [26][27] , reduced graphene oxide (rGO) 28 30 The structures of the products are comprehensively characterized and their electrochemical properties are investigated in detail. By comparing with bare CuO electrode, the CuO/GO hybrid anode delivers enhanced cycling and rate performance.…”