Composite solid electrolytes (n-C₄H₉)₄NBF₄-nanodiamonds

Nanocomposites (n-C4H9)(4)NBF4-nanodiamonds were prepared and investigated for the first time. Nanodiamonds (C-ND) with a specific surface area of 300 +/- 20 m(2)/g and grain size of 5.4 +/- 0.3 nm was taken as heterogeneous additive. According to the results of X-ray diffraction and thermal analysis studies, at high fraction of C-ND the salt transforms to the amorphous phase which is stabilized on the interfaces with the nanodiamonds particles. The thickness of the amorphous layer was estimated from the thermal analysis data as 3.5 nm. It was found that the dependence of conductivity on the C-ND fraction has a maximum 1.2 x 10(-3) S/cm at 150(degrees) C for the composition 0.02(n-C4H9)(4)NBF4-0.98C(ND) corresponding to the volume fraction of C-ND of 0.34. The conductivity was estimated using a mixing equation taking into account the concentration of the amorphous interface phase calculated from thermal analysis data. Estimation shows that conductivity of the amorphous interface phase is >3 orders of magnitude higher than that of pure (n-C4H9)(4)NBF4.