Lithium storage performance of carbon nanotubes prepared from polyaniline for lithium-ion batteries

Non-graphitic PPy-based carbon nanotubes anode materials for lithium-ion batteries

“…7, the NGCNTs contain abundant small graphite sheets stacked more or less like a 'house of cards', which provide more lithium storage active site [17]. And the NGCNTs with tubular structure lead to sufficient electrode/electrolyte interface to absorb lithium ions and promote reversibility of lithium insertion into/extraction from NGCNTs [25][26][27][28][29][30]. Meanwhile, the conducting networks constructed by interlaced tube ensure good electron transfer and enhance lithium storage, which is confirmed by the characterization of cyclic voltammetry abovementioned.…”

“…To make a clear description, comparisons of typical insertion/extraction slopes between NGCNTs and NGCGs are provided in Fig. 5c and d. Compared with NGCGs product, it can be found that the additional capacity of NGCNTs comes from the region of potential <1.5 V, which are mainly attributed to the tubular structure with larger surface areas improve material-utilization efficiency and enhance lithium storage [24][25][26][27][28].…”

“…However, the NGCGs only deliver 671.2 and 334.7 mAh g −1 during the initial discharge and charge process, respectively, with ICE of 49.8%. The initial capacity loss and the relatively low ICE of both samples may be ascribed to the formation of a SEI layer [25][26][27][28]. To make a clear description, comparisons of typical insertion/extraction slopes between NGCNTs and NGCGs are provided in Fig.…”

“…The 'house of cards' model suggests that the non-graphitic carbon contains abundant single-layer graphite sheets and the lithium could be adsorbed on both sides of the sheets. Meanwhile, it is reported that the dimension and morphology of the non-graphitic carbon are also vital to its electrochemical performance [18][19][20][21][22][23][24][25][26]. Shu et al synthesized nano-sized hard carbon spherule (HCS) with particle size between 50 and 100 nm from the distilled water/ethylene glycol mixed solution by hydrothermal technique [21].…”

“…Meduri et al synthesized the thin-walled carbon microtubes exhibiting good capacity retention of 443 mAh g −1 after 20 cycles and 135 mAh g −1 at a current density of 1.5 A g −1 [25]. Xiang et al prepared a kind of porous carbon nanotubes by carbonizing and activating of polyaniline nanotubes [26]. The activated carbon nanotubes with large surface area of 618.9 m 2 g −1 retained a high reversible capacity of 728 mAh g −1 after 20 cycles at a low current density of 100 mA g −1 .…”