Graphene as an Interfacial Layer for Improving Cycling Performance of Si Nanowires in Lithium-Ion Batteries.

Managing interfacial instability is crucial for enhancing cyclability in lithium-ion batteries (LIBs), yet little attention has been devoted to this issue until recently. Here, we introduce graphene as an interfacial layer between the current collector and the anode composed of Si nanowires (SiNWs) to improve the cycling capability of LIBs. The atomically thin graphene lessened the stress accumulated by volumetric mismatch and inhibited interfacial reactions that would accelerate the fatigue of Si anodes.

Determination of zeta potentials of polymeric nanoparticles by the conductivity variation method.

An easy method of measurement of the zeta potentials of sub-50-nm polymeric nanoparticles is suggested. Although zeta potential measurements of nanoparticles or emulsions above 50 nm have been successfully carried out, zeta potentials of emulsions or nanoparticles below 50 nm could not be precisely measured in the region of extremely low conductivity by conventional electrophoresis with a He-Ne laser. However, zeta potentials of sub-50-nm nanoparticles were measured in the region of thin electrical double layers by addition of sodium chloride and zeta potentials in the condition without sodium chloride could be predicted by extrapolation of the measured potentials.