Spontaneous Cross-linking for Fabrication of Nanohybrids Embedded with Size-Controllable Particles

This paper reports a versatile method to fabricate robust carbon/metal hybrids with ultrasmall particle and highly developed porous structure through a scalable and facile way. Alginate is used as the precursor for it could perform cross-linking reaction with different polyvalent metal ions to form gels. After simple freeze-drying and carbonization of the alginate-derived gels, we obtained the carbon/metal hybrids with fine nanostructure. Eleven kinds of metal ions were introduced to form gels and five kinds of the gels were carbonized to produce the carbon/metal hybrids. By adjusting the reaction condition, we could tune the size of the nanoparticles in the obtained hybrids. The obtained SnO2/C hybrid shows outstanding specific capacity, rate performance, and long cycle life when it is used as the anode materials of lithium ion batteries. The ultrasmall active nanoparticles were uniformly dispersed within an interconnected pore framework. It ensured a short diffusion and transportation distance of electrolyte ions to the surfaces of active nanoparticles. In addition, the robust carbon framework comprises of quasigraphitic carbon layers. It contributed to the high rate performance by providing excellent conductive pathways for electrons within the electrodes. This work provides a general method for fabrication of carbon/metal (oxide) hybrids with fine nanostructure for application in energy storage.