NOVELTY - Structure (S1) comprises a nanocomposite structure including nano-calcium carbonate lamina dispersed in a biopolymer matrix, where the nanocomposite structure is obtained from a conch shell having predetermined dimensions.    USE - The structure is useful: in a high energy storage structure which is included in a battery or a capacitor (claimed); and as ferroelectret, ferroelectric, and/or a pyroelectric material.    ADVANTAGE - The structure exhibits at least one characteristic comprising a remanent electrical polarization of 2-4 k mu C/cm2, a relative dielectric constant of 80-300 at a frequency of 100 Hz and a relative dielectric constant of 13-19 at 1 MHz, and a remanent polarization of 3000-3200 mu C/cm2 at 3.1 mHz and a remanent polarization of 2050-2250 mu C/cm2 at 0.01 Hz (claimed).    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a structure (S2) comprising a conch shell slice having predetermined dimensions and the conch shell slice has at least one characteristic comprising (a) a remanent electrical polarization of 2-4 k mu C/cm2, (b) a relative dielectric constant of 80-300 at a frequency of 100 Hz and a relative dielectric constant of 13-19 at 1 MHz, and (c) a remanent polarization of 3000-3200 mu C/cm2 at 3.1 mHz and a remanent polarization of 2050-2250 mu C/cm2 at 0.01 Hz;    (2) an energy storage structure (E1), comprising the structure (S1) or (S2);    (3) obtaining a structure, comprising slicing a conch shell to have predetermined dimensions to form a conch shell slice, where the conch shell slice has characteristics including (a)-(c) as above per se;    (4) an energy storage structure (E2), comprising a nanocomposite including nano-sized particles dispersed in a polymer matrix, where the nanocomposite is calcium carbonate powders and conch shell particles; and    (5) making an energy storage structure, comprising coating nano-sized particles with a thin layer of polymer to form core-shell particles, where the nano-sized particles are calcium carbonate powders or conch shell particles, pressing the core-shell particles together to form a sheet of nanocomposite, heating the nanocomposite material, and attaching at least one electrode to the sheet.