Tailorable Negative Permittivity of Carbon Materials Derived from Microcrystalline Cellulose at Different Carbonizing Temperature

In this work, electrical conductivity, permittivity behavior and microstructure of carbon materials derived from microcrystalline cellulose precursor at different carbonization temperature were investigated. Electrical percolation was observed with the self-constructed carbon percolative network formed. Plasma-like negative permittivity property was realized, which was well described by Drude model, resulting from the plasma oscillations of free electrons in self-constructed carbon networks. Meanwhile, magnitude and dispersion of the negative permittivity were closely associated with the carbonization temperature. This work provided a convenient way to obtain tunable negative permittivity properties with carbon materials, which have great potential in energy-storage capacitor and electromagnetic shielding applications.