## 1 Introduction  
The rapidly growing technological development of the modern world relies on the increasing demand for the allocation of energy, in the form of electrical power. While renewable energies are continuously growing worldwide, fossil fuels still show an increasing consumption associated with the production of high levels of carbon dioxide and other greenhouse gasses, which are responsible for our climate change [1]. In order to significantly reduce the usage of fossil fuels and, at the same time, increase the production of electrical power, renewable energies have to be further developed in the near future. One of the most sustainable solutions is using renewable green sources based on wind, water, or solar energy, which are clean and do not emit as much greenhouse gasses. However, renewable sources are intermittent and require efficient energy storage systems to become a valid competitor of fossil fuels. Electrochemical energy storage systems such as the Li-ion battery (LIB) represent the most promising technology to fill the gap between energy production and utilization securing energy supply. However, there are increasing concerns regarding the sustainability and criticality of materials used in LIBs, such as cobalt-containing cathode materials [2]. One of the most promising alternative Li-ion-based battery systems is the lithium-sulfur technology. Sulfur is abundant and cheap--it is considered waste by industries. Additionally, Li-S with pristine sulfur cathode yields superior high theoretical capacity (1672 mAh/g) and gravimetric energy (2500 Wh/kg) [3]. Nevertheless, the electrically insulating nature of sulfur and lithium sulfide, its poor cycling performance, due to the high polysulfides solubility and large volume (80%) changes during the redox reaction, impede the use of sulfur as cathode material. Thus, designing a highly efficient Li-sulfur system still remains a challenge. For tackling above issues, various strategies have been suggested. Providing skeleton materials with porous structure to reduce the \"shuttle effect\" and volume expansion of sulfur, as well as incorporating conductive materials to increase the electrical conductivity, are the main methods for enhancing the electrochemistry performance of lithium-sulfur batteries (LSB) [4; 5; 6; 7]. In the past decade, nanomaterials, such as graphene, carbon nanotubes, porous carbon, and SiC, as well as nitrogen-doped carbonaceous materials, are widely investigated as skeleton and conductive materials for Li-S batteries, and they indeed lead to an improvement of the electrochemical performance of the sulfur cathode [8; 9; 10; 11; 12; 13; 14; 15; 16; 17]. However, most of the applied nanomaterials are expensive in production; therefore, their practical large-scale commercialization is hard to achieve. For normal porous carbon materials, their soft structure is not enough to hamper the volume expansion during the battery cycling process. Thus, there is still a big demand for the development of an advanced host material, which is not only mechanically flexible and robust, but also shows enhanced conductivity and can be produced at low costs. C-rich polymer derived ceramics (PDCs) are remarkable materials, due to their robust architecture, suitable to restrain volume changes and tunable electrical conductivity providing pathways for electrons and ions [18; 19; 20; 21; 22]. In addition, their porous property makes it possible to load sulfur and to realize physical adsorption barrier for polysulfides to hamper the \"shuttle effect\" [23; 24; 25; 26]. Our previous work showed that porous C-rich SiCN ceramics pyrolyzed at temperatures between 1000 \({}^{\circ}\)C and 1600 \({}^{\circ}\)C can stabilize the electrochemical behaviour of sulfur [27]. It has been also demonstrated that the morphology of C-rich SiCN ceramics significantly affects the electrochemical performance of the S/SiCN composites and nitrogen contained in the ceramic matrix has a stabilizing effect for the electrochemical performance.