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Li-ion capacitors, comprising a battery anode and a supercapacitor cathode, have been expected to bridge the gap between batteries and supercapacitors. However, the kinetics mismatch between the anodic sluggish insertion and the cathodic capacitive process has impeded the energy-storage potential of devices. Developing pseudocapacitive anode materials is urgently needed in that pseudocapacitance can deliver energy in the same time scale as electrostatic adsorption and offer a comparable level of energy storage to that of battery-type materials. Here we demonstrate an inside and outside synergistic nanoengineering strategy to synthesize nanoporous carbonmodified S-TiO 2 hybrid nanosheets, through which both the carbon layer and sulfur doping can be simultaneously generated in situ. Benefiting from the in situ S doping, the electronic and ionic conductivity of anatase TiO 2 nanoparticles is enhanced. The carbon-modified S-TiO 2 with dominant pseudocapacitance realizes an unprecedentedly high capacity of 550 mAh g −1 at 0.3 C and excellent rate capability, outperforming that of the ever-reported TiO 2 -based materials. Furthermore, a hybrid Li-ion capacitor based on the as-obtained carbon-modified S-TiO 2 electrode has been assembled, delivering a high energy density of 92.7 Wh kg −1 and power density of 26 kW kg −1 with a stable cycling life (85.8% after 10 000 cycles). Our work offers a new avenue for achieving electrode materials with extrinsic pseudocapacitance that is kinetically comparable to capacitive materials.

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[1] The analytical results of the acidity and buffering capacity of particulate matter sampled by aircraft over Chinese eastern coastal areas in March and early April 2002 are presented. The flight region covered the coastal areas from Zhuhai, Guangdong province, to Dalian, Liaoning province, and the northeastern coastal areas around Dalian, Liaoning province, with the later being the key flight areas. The results show that total suspended particles (TSP) generally appear to be acidic, having no buffering capacity for acidification; the acidity of TSP in northern areas is lower than that in southern areas, whereas the acidity of TSP in the bordering region of the northern areas and the southern areas is relatively high, the discrimination of the acidity of TSP in different areas could be up to more than 100 times. The acidity of particulate matter increases as its diameter decreases, indicating that fine particles have strong acidity. Both in northern areas and in southern areas, particulate matter with diameters larger than 11 m has acidic buffering capacity, but particulate matter with diameters smaller than 2.1 m appears to be acidic, having no buffering capacity. Although the pollution level of particulate matter at high altitudes is lower, its acidification is stronger than that at ground level. The regional acidification of particulate matter at high altitudes is an important reason why some areas in China suffer acidic precipitation.