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To enhance the electrochemical performance, a conventional activated carbon supercapacitor is modified by adopting potassium-polyacrylate (PAAK) electrolyte additive on a glass fiber separator and by fabricating the activated carbon electrode on nickel foam instead of on conventional nickel foil as a current collector. The glass fiber separator plays the role of self-supporting PAAK-KOH hydrogel electrolyte with superior ionic conductivity. Moreover, the adoption of nickel foam strengthens the close contact between the active material and the current collector, reducing the interfacial resistance between electrode and electrolyte. As a result, the combination of glass fiber separator and nickel foam substrate can contribute to a great increase in the specific capacitance, to a value of over 200 F g−1, and to an enhancement of the high-rate capability of activated carbon supercapacitors.

A facile direct hybridization route to prepare SnO2/graphene nanocomposites for Li-ion battery anode application is demonstrated. Uniform distribution of SnO2 nanoparticles on graphene layers was enabled by a one-step chemical synthetic route. The optimal content ratio of SnO2 and graphene was determined from microscopic observations and electrochemical studies. The nanocomposite anode with SnO2 loading level of around 70 wt.% retained reversible capacity of 643.6 mAh/g after 50 cycles and high discharge capacity of 347.8 mAh/g at a current density of 3000 mA/g, which was superior to that of graphene-only electrodes or nanocomposites with overloaded SnO2 nanoparticles. Taking advantage of nano-sized SnO2 and an electrically conductive and mechanically flexible graphene layer, SnO2/graphene nanocomposites with optimized SnO2 content exhibit excellent electrochemical properties as lithium-ion battery anodes. Our strategy offers a straightforward and high-throughput pathway for creating and directing graphene-based functional hybrids through simple mixing and thermal treatments, and may be used to assemble high-performance Li-ion batteries.

For use as an anode material in lithium batteries, composites consisting of TiO2 nanotubes (TNTs) and carbon nanotubes (CNTs) are prepared by combining hydrothermal reaction of rutile TiO2 bulk particles, blending with different amounts (0–30 wt.%) of CNTs, ball-milling, and subsequent heat treatment at 300 °C. Crystalline property analysis and morphology observation of the prepared TNT-CNT powders prove that at low CNT content the composites are consisted of dominant phase of aggregated anatase TNTs. The TNT aggregates are relaxed with increased CNT content to form crosslinked networks surrounding the amorphous CNT phases that act as a dispersing matrix. As a result, the TNT-CNT composite anode with CNT (30 wt.%) is superior for application in lithium-ion batteries because it shows a saturated discharge capacity after about 20th cycle, good high-rate capability, and the lowest interfacial resistance of 1.7–2 Ω cm−2. The superior anode properties of TNT-CNT composite with high content of CNT are mainly due to CNT’s functions to enhance electron transfer and to facilitate Li+ diffusion by dispersing the TNT agglomeration.