CFx/SiO2 composites with different SiO2 sources have been synthesized as cathode materials for primary lithium batteries. The effect of modification with different SiO2 sources on the performance of CFx has been investigated with FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM), BET, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements (galvanostatic discharge, EIS). Based on the FT-IR and XPS analyses, it is confirmed that semi-ionic C–F has existed in SiO2 modified CFx and the F/C has decreased which may be caused by the reaction between SiO2 and CF2. The BET illustrated that the surface area of SiO2 modified CFx was extremely larger than that of pristine CFx. Furthermore, electrochemical measurements displayed an enhancement in the discharge capacity and plateau of the CFx/SiO2 composites, as well as an improvement in their power density and energy density. In particular the CFx–mSiO2 exhibits a discharge capacity of 587 mA h g−1, with a plateau of 2.28 V at a current density of 5C, accompanied by a maximum power density of 9689 W kg−1 and about three times higher energy density than that of pristine CFx.

•PtAuCu nanocatalyst is synthesized via a simple galvanic displacement method.•After dealloying, a rich PtAu skin is exposed on the surface of the PtAuCu.•Dealloyed PtAuCu is demonstrated with enhanced ORR activity and superior stability.•Dealloyed PtAuCu displays excellent MOR activity and CO tolerance ability.•The high catalytic activity is due to geometric, electronic structural effect.In the present work, we synthesize ternary PtAuCu nanoparticles supported on carbon by a sequent galvanic displacement method and study the relationship between the structure and properties. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) reveal that PtAuCu displays a compressive lattice, and X-ray photoelectron spectroscopy (XPS) also presents an altered electronic environment. After electrochemical dealloying, a rich PtAu skin is exposed on the surface of the PtAuCu. With the changes in the geometric, electronic and surface structure, the PtAuCu electrocatalyst shows an enhancement in ORR and MOR activity, as well as an improvement in their stability. The Pt10Au10Cu64/C catalyst exhibits a Pt mass activity of 0.376 A mgPt−1 at 0.85 V for the ORR, which is 2.22 times higher than that of Pt/C, and the current density at 0.8 V for the MOR is 4.43 times higher than that of Pt/C. Furthermore, Pt10Au3Cu44/C exhibits superior stability for the ORR, with a mass activity loss of only 7.25% after 3000 cycles, whereas Pt/C exhibits a 48.82% loss under the same conditions.

Three-dimensional porous Cu/Cu2O, CuO, CuO/NiO were prepared on Ni foam by a simple two step method which consist of a replacement reaction and subsequent thermal treatment method at various temperature. The morphology and microstructure of the samples were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical properties of the samples were evaluated by galvanostatic discharge–charge cycling, cyclic voltammetry and impedance spectral measurements on cells with lithium discs as counter electrode and reference electrode. Compared to Cu/Cu2O and CuO/NiO, the sample of CuO obtained at 400 °C exhibited the best electrochemical performance which delivered a reversible capacity of 605.3 mAh g−1 (89.8% of the theoretical capacity) after 50 cycles at the current density of 100 mA g−1, without noticeable capacity fading. The excellent electrochemical performance of porous CuO can be attributed to the three-dimensional porous structure, which cannot only provide large surface area but also facilitate Li+ and electron transfer, and the strong connection between active materials and Ni foam can promote better intrinsic kinetics.

Controlling the morphologies of Pt nanocrystals provide effective opportunities to promote the electrochemical properties and enhance the mass activity. Recently we have reported that Pluronic F127 (PEO100PPO65PEO100) could serve as reducing reagent for synthesis of highly electrocatalytic activity of branched Pt nanocrystal. Herein, we further synthesize another novel Pt nanosponge foil (Pt-NSF) under the same system with Pluronic F127. We expect to build the relationship between block copolymer system and morphology design of synthesized nanocrystal with specific electrochemical property. The electrochemical active areas (ECSA) of Pt-NSF and Pt-black are of the order of 20 m2 g−1. On one hand, step atoms, dislocations, grain boundaries, which observed from HRTEM (high resolution transmission electron microscope), are all prevalent on Pt-NSF, which could serve as active adsorption sites. On the other hand, Pt-NSF looks like an aggregation of many Pt-black nanoparticles, the connection formed skeleton is conducive to electron transfer. These reasons aroused the mass activity and the specific activity of Pt-NSF were much higher than each of Pt-black toward the oxygen reduction reaction activity (ORR) at 0.9 V respectively. Durability tests show that the ECSA of Pt-NSF and Pt-black declined, but the activity of Pt-NSF toward the ORR was almost unchanged. The impact of structures on the electrochemical properties is described in detail.

New nano/submicron branched platinum (B-Pt) was readily synthesized by auto-reduction reflux of H2PtCl6 solution mixed with poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (Pluronic F127, PEO100PPO65PEO100). The as-prepared B-Pt shows many interconnected fractal twigs with the diameter of each branch at nano-level though the whole B-Pt array is relatively large at submicron size. High resolution transmission electron microscopy (HRTEM) shows that the B-Pt generally exposed (111) planes and possesses a high density of edges and corners, widespread lattice distortions, step and suspension atoms, which are all beneficial for electrocatalysis. Electrochemical tests, comparing the kinetic current, further confirmed that the oxygen reduction reaction (ORR) activity of the B-Pt was better than that of current commercial Pt black and Pt/C catalysts. The copolymer serves as reducing, protecting and orienting agent at the same time and the growth mechanism of B-Pt is described in detail.

Cobalt antimonide, CoSb3, has been prepared by vacuum melting and ball-milling. The electrochemical cycling behaviors of CoSb3 were evaluated using lithium anode model cell Li∣LiPF6 (EC + DMC)∣CoSb3. The reversible capacities of CoSb3 intermetallic electrode reached 570 and 290 mAh g− 1, respectively for the first cycle and the twentieth cycle. It was demonstrated that cycle stability of CoSb3 could be largely improved by milling after mixing with mesocarbon microbeads. There were 50.9% and 77.5% retention of the initial capacity at the twentieth cycle, respectively for CoSb3 and CoSb3–MCMB hybrid.

CFx/SiO2 composites with different SiO2 sources have been synthesized as cathode materials for primary lithium batteries. The effect of modification with different SiO2 sources on the performance of CFx has been investigated with FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM), BET, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements (galvanostatic discharge, EIS). Based on the FT-IR and XPS analyses, it is confirmed that semi-ionic C–F has existed in SiO2 modified CFx and the F/C has decreased which may be caused by the reaction between SiO2 and CF2. The BET illustrated that the surface area of SiO2 modified CFx was extremely larger than that of pristine CFx. Furthermore, electrochemical measurements displayed an enhancement in the discharge capacity and plateau of the CFx/SiO2 composites, as well as an improvement in their power density and energy density. In particular the CFx–mSiO2 exhibits a discharge capacity of 587 mA h g−1, with a plateau of 2.28 V at a current density of 5C, accompanied by a maximum power density of 9689 W kg−1 and about three times higher energy density than that of pristine CFx.