The rechargeable Li-CO2 battery is a novel and promising energy storage system with the capability of CO2 capture due to the reversible reaction between lithium ions and carbon dioxide. Carbon materials as the cathode, however, limit both the cycling performance and the energy efficiency of the rechargeable Li-CO2 battery, due to the insulating Li2CO3 formed in the discharge process, which is difficult to decompose in the charge process. Here, a Mo2C/carbon nanotube composite material is developed as the cathode for the rechargeable Li-CO2 battery and can achieve high energy efficiency (77%) and improved cycling performance (40 cycles). A related mechanism is proposed that Mo2C can stabilize the intermediate reduction product of CO2 on discharge, thus preventing the formation of insulating Li2CO3. In contrast to insulating Li2CO3, this amorphous Li2C2O4-Mo2C discharge product can be decomposed below 3.5 V on charge. The introduction of Mo2C provides an effective solution to the problem of low round-trip efficiency in the Li-CO2 battery.

Mixed metal oxides have been attracting more and more attention recently because of their advantages and superiorities, which can improve the electrochemical performance of single metal oxides. These advantages include structural stability, good electronic conductivity, and reversible capacity. In this work, uniform yolk-shelled ZnCo 2 O 4 microspheres were synthesized by pyrolysis of ZnCo-glycolate microsphere precursors which were prepared via a simple refluxing route without any precipitant or surfactant. The formation process of the yolk-shelled microsphere structure during the thermal decomposition of ZnCoglycolate is discussed, which is mainly based on the heterogeneous contraction caused by nonequilibrium heat treatment. The performances of the as-prepared ZnCo 2 O 4 electrodes using sodium carboxylmethyl cellulose (CMC) and poly-vinylidene fluoride (PVDF) as binders are also compared.Constant current and rate charge-discharge testing results demonstrated that the ZnCo 2 O 4 electrodes using CMC as the binder had better performance than those using PVDF as the binder. It was worth pointing out that the electrode using CMC as the binder nicely yields a discharge capacity of 331 mA h g À1 after 500 cycles at a current density of 1000 mA g À1 , which is close to the theoretical value of graphite (371 mA h g À1 ). Furthermore, the obtained synthetic insights on the complex hollow structures will be of benefit to the design of other anode materials for lithium ion batteries.

Sodium-ion batteries (SIBs) have been attracting intensive attention at present as the most promising alternative to lithium-ion batteries in large-scale electric storage applications, due to the low-cost and natural abundance of sodium. Elemental phosphorus (P) is very promising anode material for SIBs, with the highest theoretical capacity of 2596 mAh g −1 . Recently, there have been many efforts devoted to phosphorus anode materials for SIBs. As pure red phosphorus can not react with Na reversibly, many attempts to prepare composite materials containing phosphorus have been reported. Here, we report the facile preparation of a red phosphorus/N-doped carbon nanofiber composite (P/NCF) that can deliver a reversible capacity of 731 mAh g -1 in sodium-ion batteries (SIBs), with capacity retention of 57.3 % over 55 cycles. Our results suggest that it would be a promising anode candidate for SIBs with a high capacity and low cost.

Palladium-Nickel (Pd-Ni) hollow nanoparticles were synthesized via a modified galvanic replacement method using Ni nanoparticles as sacrificial templates in an aqueous medium. X-ray diffraction and transmission electron microscopy show that the as-synthesized nanoparticles are alloyed nanostructures and have hollow interiors with an average particle size of 30 nm and shell thickness of 5 nm. Compared with the commercially available Pt/C or Pd/C catalysts, the synthesized PdNi/C has superior electrocatalytic performance towards the oxygen reduction reaction, which makes it a promising electrocatalyst for alkaline anion exchange membrane fuel cells and alkali-based air-batteries. The electrocatalyst is finally examined in an H2/O2 alkaline anion exchange membrane fuel cell; the results show that such electrocatalysts could work in a real fuel cell application as a more efficient catalyst than state-of-the-art commercially available Pt/C.

(2013). A unique sandwich-structured C/Ge/graphene nanocomposite as an anode material for high power lithium ion batteries. Journal of Materials Chemistry A, 1 (45), 14115-14121. A unique sandwich-structured C/Ge/graphene nanocomposite as an anode material for high power lithium ion batteries AbstractA unique sandwich-structured C/Ge/graphene composite with germanium nanoparticles trapped between graphene sheets is prepared by a microwave-assisted solvothermal reaction followed by carbon coating and thermal reduction. The graphene sheets are found to be effective in hindering the growth and aggregation of GeO2 nanoparticles. More importantly, the graphene sheets, coupled with the carbon coating, can buffer the volume changes of germanium in electrochemical lithium reactions. The unique sandwich structure features a highly conductive network of carbon, which can improve both the conductivity and the structural stability of the electrode material, and exemplifies a promising strategy for the development of new high performance electrode materials for lithium ion batteries. A unique sandwich-structured C/Ge/graphene composite with germanium nanoparticles trapped between graphene sheets is prepared by a microwave-assisted solvothermal reaction followed by carbon coating and thermal reduction. The graphene sheets are found to be effective in hindering the growth and aggregation of GeO 2 nanoparticles. More importantly, the graphene sheets, coupled with the carbon coating, can buffer the volume changes of germanium in electrochemical lithium reactions.The unique sandwich structure features a highly conductive network of carbon, which can improve both the conductivity and the structural stability of the electrode material, and exemplifies a promising strategy for the development of new high performance electrode materials for lithium ion batteries.