A tube-in-tube carbon nanostructure (TTCN) with multi-walled carbon nanotubes (MWNTs) confined within hollow porous carbon nanotubes is synthesized for Li-S batteries. The structure is designed to enhance the electrical conductivity, hamper the dissolution of lithium polysulfide, and provide large pore volume for sulfur impregnation. As a cathode material for Li-S batteries, the S-TTCN composite with 71 wt% sulfur content delivers high reversible capacity, good cycling performance as well as excellent rate capabilities.

Filled to capacity: Calix[4]quinone (C4Q) has eight available carbonyl groups for binding lithium ions (see picture). It can be exploited to prepare quasi‐solid‐state rechargeable lithium batteries with a poly(methyl acrylate)/poly(ethylene glycol) based gel polymer electrolyte and a LiClO4/DMSO loading. It shows an initial discharge capacity of 422 mA h g−1 and a capacity retention of 379 mA h g−1 after 100 cycles.

expected to be a promising candidate for emerging smart grid technology in the near future. Nevertheless, the scarcity and uneven distribution of lithium resources hamper its further development. In pursuit of alternatives to LIBs for large-scale applications, sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) have great potential, owing to the low cost and high abundance of Na (2.36 wt%) and K (2.09 wt%) in the Earth's crust, as well as its similar chemical properties to those of lithium. [1][2][3][4][5] Much work so far has focused on SIBs, and significant progress has been achieved in the past few years. [6][7][8] On the contrary, the development of PIBs is still in its infancy, probably due to the larger ionic radius of K + (1.38 Å) than those of Na + (1.02 Å) and Li + (0.76 Å). [9] However, PIBs possess several advantages compared with SIBs, such as the more negative standard potential of K + /K (−2.93 V vs SHE, compared with −2.71 V for Na + / Na), reversible intercalation/deintercalation of K + in graphite (theoretical capacity of 279 mA h g −1 ), and fast ionic conductivity of K + in liquid electrolyte. [10][11][12] These properties of PIBs offer exciting opportunities to achieve low-cost batteries with high energy density and good rate performance. Nevertheless, it remains challenging to fabricate suitable electrode materials, The potassium-ion battery (PIB) represents a promising alternative to the lithium-ion battery for large-scale energy storage owing to the abundance and low cost of potassium. The lack of high performance anode materials is one of the bottlenecks for its success. The main challenge is the structural degradation caused by the huge volume expansion from insertion/extraction of potassium ions which are much larger than their lithium counterparts.Here, this challenge is tackled by in situ engineering of a yolk-shell FeS 2 @C structure on a graphene matrix. The yolk-shell structure provides interior void space for volume expansion and prevents the aggregation of FeS 2 . The conductive graphene matrix further enhances the charge transport within the composite. The PIB fabricated using this anode delivers high capacity, good rate capability (203 mA h g −1 at 10 A g −1 ), and remarkable long-term stability up to 1500 cycles at high rates. The performance is superior to most anode materials reported to date for PIBs. Further in-depth characterizations and density functional theory calculations reveal that the material displays reversible intercalation/deintercalation and conversion reactions during cycles, as well as the low diffusion energy barriers for the intercalation process. This work provides a new avenue to allow the proliferation of PIB anodes.

Atomic chains and crystal of iodine were successfully generated in a controlled manner inside single-walled carbon nanotubes (SWNTs). The structure is strongly dependent on the diameter of SWNTs; the single, double, and triple helical structures became quite stable when the diameter of SWNTs matches the certain size. More than three chains of iodine are not very stable, and they often crystallize inside the carbon nanotube when the diameter is larger than 1.45 nm. The crystallization or phase transition in a confined nanospace is thus directly observed, and there is indeed a critical size of the hollow nanospace for the stable formation of the atomic chains of iodine.

S and N co-doped, few-layered graphene oxide is synthesized by using pyrimidine and thiophene as precursors for the application of the oxygen reduction reaction (ORR). The dual-doped catalyst with pyrrolic/graphitic N-dominant structures exhibits competitive catalytic activity (10.0 mA cm(-2) kinetic-limiting current density at -0.25 V) that is superior to that for mono N-doped carbon nanomaterials. This is because of a synergetic effect of N and S co-doping. Furthermore, the dual-doped catalyst also shows an efficient four-electron-dominant ORR process, which has excellent methanol tolerance and improved durability in comparison to commercial Pt/C catalysts.

A self-powered integrated strain sensor system which could be attached to the human body to detect human motion was developed.

This work provides a novel and simple way to prepare hydrogel electrolytes with eminent toughness, high conductivity and anti-freezing properties.

Recently, many studies have shown the potential use of circulating exosomes as novel biomarkers for monitoring and predicting a number of complex diseases, including cancer. However, reliable and cost-effective detection of exosomes in routine clinical settings, still remain a difficult task, mainly due to the lack of adequately easy and fast assay platforms. Therefore, we demonstrate here the development of a visible and simple method for the detection of exosomes by integrating single-walled carbon nanotubes that being excellent water solubility (s-SWCNTs) and aptamer. Aptamers, specific to exosomes transmembrane protein CD63, are absorbed onto the surface of s-SWCNTs and improve the minic peroxidase activity of s-SWCNTs, which can efficiently catalyze HO-mediated oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) and lead to a change from colorless to blue in solution. However, after adding exosomes, the aptamers are bound with CD63, leaving from the surface of s-SWCNTs through conformational changes, which results the color of solution from deep to moderate, and this can be observed by the naked eye and monitored by UV-vis spectrometry. Under optimal conditions, the linear range of exosomes is estimated to be 1.84×10 to 2.21×10 particles/μL with a detection of limit (LOD) of 5.2×10 particles/μL. Consequently, a visible and simple approach detecting exosomes is successfully constructed. Moreover, this proposed colorimetric aptasensor can be universally applicable for the detection of other targets by simple change the aptamer.