An electrically conductive and electrochemically active composite paper of graphene nanosheet (GNS) coated cellulose fibres was fabricated via a simple paper-making process of dispersing chemically synthesized GNS into a cellulose pulp, followed by infiltration. The GNS nanosheet was deposited onto the cellulose fibers, forming a coating, during infiltration. It forms a continuous network through a bridge of interconnected cellulose fibres at small GNS loadings (3.2 wt%). The GNS/cellulose paper is as flexible and mechanically tough as the pure cellulose paper. The electrical measurements show the composite paper has a sheet resistance of 1063 Ω□(-1) and a conductivity of 11.6 S m(-1). The application of the composite paper as a flexible double layer supercapacitor in an organic electrolyte (LiPF(6)) displays a high capacity of 252 F g(-1) at a current density of 1 A g(-1) with respect to GNS. Moreover, the paper can be used as the anode in a lithium battery, showing distinct charge and discharge performances. The simple process for synthesising the GNS functionalized cellulose papers is attractive for the development of high performance papers for electrical, electrochemical and multifunctional applications.

A nanocomposite anode material for lithium batteries is designed and fabricated by the insertion of graphite nanosheets (GNS) into the ceramic network of silicon oxycarbide (SiOC) ceramics for the development of structurally and electrochemically stable lithium batteries. The GNS forms a layered phase in the SiOC ceramic network from the self-assembly of graphite oxides (GO) introduced in a polysiloxane precursor through thermal transformations after pyrolysis. The composite anode (GNS/ SiOC) exhibits an initial discharge capacity attaining 1141 mAh g À1 . The discharging capacity decreases in the first eight cycles and stays at 364 mAh g À1 in the following cycles. This reversible discharging capacity is higher than that of a graphite reference (328 mAh g À1 ) and a SiOC monolithic. Correlating the discharge capacities to the material compositions and structures suggest that the interface between SiOC and GNS contributes to the enhanced capacity of the composite anode, in addition to those from GNS and SiOC. Further increasing the electrochemical performance is possible by the increase of the amount of GNS in the composite.

Polymer‐derived SiCN materials, pyrolyzed from polysilylethylenediamine at temperatures between 600° and 1500°C, are used as the anode in lithium batteries, and their electrochemical performance is studied. The SiCN materials, having composition ranging from organic to inorganic and phase structures from amorphous to crystalline, are obtained from pyrolysis at different temperatures. Electrochemical measurements show that the 1000°–1300°C derived SiCN materials exhibit a first‐cycle discharge capacity of 608–754 mAh/g at a current density of 40 mA/g, which is higher than that of a graphite anode. The discharge capacity reduces to 170–230 mAh/g after seven charge–discharge cycles and stays in this range over 30 cycles. Compositional and structural analyses show that the 1000°–1300°C derived SiCN materials have an amorphous phase and contain free carbon in the SiCN network. In contrast, the 600°–800°C derived SiCN, which contains organic groups, and the 1400°–1500°C derived SiCN, which contains SiC crystallites, show a much lower charge and discharge capacity compared with that of the amorphous SiCN anode. This suggests that free carbon in SiCN and the amorphous structure of the SiCN materials contribute to the electrochemical performance of the SiCN materials. It seems that the free carbon phase acts as an active site for the insertion of Li ions while the amorphous SiCN network provides a path for Li‐ion transfer. The strong dependence of the electrochemical capacities of the polymer‐derived SiCN materials on their compositions and structures suggests the potential to enhance the electrochemical performance of the materials through molecular design and/or the control of material structure.

Bulk Si(O)C ceramics are fabricated from polycarbosilane (PCS) by bulk pyrolysis along the route of cross linking, warm‐pressing, and pyrolysis. The PCS was thermally oxidized for cross linking at various temperatures as a critical step toward the bulk transformation of PCS into bulk Si(O)C ceramics. The degree of cross linking of PSC affects the densities and bonding qualities of the warm‐pressed powder compacts and, hence, the resultant ceramics. Under optimized processing conditions, crack‐free bulk Si(O)C ceramics are obtained with a bulk density attaining 2.2 g/cm3. Despite the existence of a considerable amount of oxygen in the ceramics (16.08 wt%), resulting from the thermal oxidation processing, the ceramics show the characteristics of structures and properties of SiC‐based ceramics. 29Si‐solid state nuclear magnetic resonance spectra (NMR) reveal that the as‐pyrolyzed X‐ray amorphous Si(O)C phase consists mainly of SiC4 coordination units in the ceramic network, with the remainder being silicon‐coordinated carbon and oxygen. Microhardness tests show that the as‐pyrolyzed amorphous Si(O)C ceramics have a high hardness, attaining 24.91 GPa at a load of 2 N, and 19.82 GPa at a load of 10 N. Upon annealing at 1300°C in argon, the amorphous ceramics crystallized into nanophase β‐SiC ceramics, and the ceramics kept the bulk nature of the amorphous ceramics with an increased density. The 29Si‐solid state NMR spectrum indicates that the nanophase β‐SiC ceramics consist of SiC4 units together with some mixed coordination units, namely SiO2C2 and SiOC3. The hardness of the crystallized nanophase Si(O)C ceramics attains 23.20 GPa at a load of 10 N. The present study demonstrates the possibility of fabricating bulk Si(O)C ceramics via the polymer‐processing route, resulting in ceramics with promising structural and mechanical properties.