For building high‐energy density asymmetric supercapacitors, developing anode materials with large specific capacitance remains a great challenge. Although Fe2O3 has been considered as a promising anode material for asymmetric supercapacitors, the specific capacitance of the Fe2O3‐based anodes is still low and cannot match that of cathodes in the full cells. In this work, a composite material with well dispersed Fe2O3 quantum dots (QDs, ≈2 nm) decorated on functionalized graphene‐sheets (FGS) is prepared by a facile and scalable method. The Fe2O3 QDs/FGS composites exhibit a large specific capacitance up to 347 F g−1 in 1 m Na2SO4 between –1 and 0 V versus Ag/AgCl. An asymmetric supercapacitor operating at 2 V is fabricated using Fe2O3/FGS as anode and MnO2/FGS as cathode in 1 m Na2SO4 aqueous electrolyte. The Fe2O3/FGS//MnO2/FGS asymmetric supercapacitor shows a high energy density of 50.7 Wh kg−1 at a power density of 100 W kg−1 as well as excellent cycling stability and power capability. The facile synthesis method and superior supercapacitive performance of the Fe2O3 QDs/FGS composites make them promising as anode materials for high‐performance asymmetric supercapacitors.

Al ion conductive solid polymer electrolyte is prepared using poly(vinylidene fluoride) (PVdF) and AlCl 3 as a host polymer and Al ion salt, respectively. AlCl 3 salt can be dissolved into PVdF and uniformly distributed in the polymer up to F/Al ratio is 8. With further increase in the AlCl 3 content, a phase separation of AlCl 3 and PVdF is observed. It is noted that melting and amorphization temperatures of PVdF are also affected by the content of AlCl 3 . The melting temperature and promotion of crystallization of PVdF decrease with increase in AlCl 3 until F/Al to be 8. With further increase in AlCl 3 , the melting and crystallization temperature increase. Through FT-IR characterization, it is observed that characteristic frequency peaks relating CF vibration shift with addition of AlCl 3 , indicating that Al cation interacts with F in the PVdF host. The highest conductivity is 4.4 × 10 −4 S cm −1 at room temperature is achieved at F/Al ratio equaling 8. The cation transference number of this Al polymer electrolyte is 0.24 which is close to that of PVdF-based Li ion conductive polymer. The electrochemical stable window of the PVdF-AlCl 3 polymer at F/Al ratio of 8 is 0 ∼ 2.4 V vs. Al 3+ /Al. The electrochemical stable window covers redox voltages of most reported cathode materials for rechargeable Al batteries, implying that this PVdF-based polymer electrolyte can be a good candidate for the Al batteries.

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LiNi0.5Mn1.5O4 nanorods wrapped with graphene nanosheets have been prepared and investigated as high energy and high power cathode material for lithium-ion batteries. The structural characterization by X-ray diffraction, Raman spectroscopy, and Fourier transform infrared spectroscopy indicates the LiNi0.5Mn1.5O4 nanorods prepared from β-MnO2 nanowires have ordered spinel structure with P4332 space group. The morphological characterization by scanning electron microscopy and transmission electron microscopy reveals that the LiNi0.5Mn1.5O4 nanorods of 100–200 nm in diameter are well dispersed and wrapped in the graphene nanosheets for the composite. Benefiting from the highly conductive matrix provided by graphene nanosheets and one-dimensional nanostructure of the ordered spinel, the composite electrode exhibits superior rate capability and cycling stability. As a result, the LiNi0.5Mn1.5O4-graphene composite electrode delivers reversible capacities of 127.6 and 80.8 mAh g−1 at 0.1 and 10 C, respectively, and shows 94% capacity retention after 200 cycles at 1 C, greatly outperforming the bare LiNi0.5Mn1.5O4 nanorod cathode. The outstanding performance of the LiNi0.5Mn1.5O4-graphene composite makes it promising as cathode material for developing high energy and high power lithium-ion batteries.

Immiscibility between polymer and ionic liquid, and the loss of solid-state configuration when ionic liquid loading becomes too high have been addressed by creating poly(ethylene oxide)-immobilized ionogel through a facile mechanochemical method. The poly(ethylene oxide)-immobilized ionogel with ionic liquid loading as high as 50 wt% demonstrates a high room-temperature ionic conductivity in the order of 10 −4 S cm −1 .

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