With the development of renewable energy in recent years, supercapacitors - energy storage devices - have received global attention due to their high power density, short charging time and outstanding cycle stability. They hold great promise for future highly integrated, flexible and portable electronic systems, which are highly required by modern technological society. The limitation of the application of supercapacitors on a large scale comes from their low energy storage density and relatively high effective series resistance. Hence, it is of great importance to achieve high - performance supercapacitors via design and synthesis of novel electrode materials with rational structure and composition for meeting the requirements of ideal electrodes. Therefore, the overall objective of the project was to develop self-assembling and self-activation strategy to produce N/P dual-doped 3D carbon network by nano-CaCO3 template-assistant carbonization of intumescent flame retardants (IFRs) chosen for their interesting features such as presence of heteroatoms (N, P), tailored composition and easy carbonization to form porous char (2D carbon sheets).