## 3 SiCN-Based Anode Materials  
The SiCN is obtained by pyrolysis of polysilazane precursors. Diverging from SiOC systems, amorphous silicon carbonitride (SiCN) ceramics exhibit precursor-dependent microstructural configurations that may lack defined SiC\({}_{\text{x}}\)N\({}_{\text{y}}\) moieties (featuring Si-C/N bonding). Structural analysis in Figure 8 illustrates this dichotomy: polysilazane-derived SiCN contains tetrahedral Si centers coordinated exclusively with N, C, or their hybrid configurations (SiC\({}_{\text{d}}\), SiN\({}_{\text{4}}\), or SiC\({}_{\text{x}}\)N\({}_{\text{y}}\)), while counterparts synthesized from polysilocarbodiimide manifest a triphasic amorphous architecture comprising Si\({}_{\text{3}}\)N\({}_{\text{4}}\), SiC, and free carbon nanodomains, with complete absence of SiO\({}_{\text{4-x}}\)C\({}_{\text{x}}\) units. SiCN material has a robust three-dimensional network structure with chemical resistance, thermal stability and oxidation resistance [40; 41]. It can ensure the stability of the electrode material structure during charging and discharging processes, thereby improving the performance of batteries. Its research as an anode material has become one of the hotspots in lithium-ion batteries [42]. In 1997, [PERSON] et al. [30] first prepared SiCN ceramics using thermal decomposition of polysilazane and used it as a anode material for lithium-ion batteries. The study found that its reversible capacity can reach up to 560 mAh-g\({}^{-1}\). Upon discovering that SiCN material possesses high charge and discharge capacities and exceptional properties, [PERSON]'s team identified two structural advantages that render it suitable as an active material for lithium-ion battery anodes [43]. Firstly, the SiCN network contains numerous nanoclusters and free dangling bonds between silicon and carbon, serving as active sites for lithium-ion intercalation/de-intercalation and boasting high electrochemical capacity. Secondly, the nanoholes or nanochannels within the SiCN network offer numerous smooth channels for lithium-ion transport, thereby facilitating  
Figure 7: (**a**) Synthesis and structure diagram of Cu-Si/SiOC. (**b**) XRD patterns of SiOC-based samples. (**c**) XRD pattern of Cu-Si/SiOC. (**d**) Raman spectra, (**e**) FTIR spectra, and (**f**) high-resolution Si 2p spectra of SiOC-based samples. (**g**) High-resolution Cu 2p spectrum of Cu-Si/SiOC. Copied with permission from [PERSON] [37]. superior electrochemical kinetic performance. Consequently, they employed 1000 \({}^{\circ}\)C argon gas heat treatment to fabricate SiCN-CNTs (10 wt% CNTs) composites. Charge and discharge cycling tests revealed that their initial specific discharge capacity was 1.5 times that of pure SiCN, signifying a notable enhancement and improving the material's conductivity. Contemporary investigations into silicon carbonitride (SiCN) anodes fabricated via polymer-derived ceramic (PDCs) routes predominantly concentrate on thermochemical modulation; specifically, the controlled pyrolysis temperature parameters governing their charge storage capabilities and electrochemical stability. [PERSON] et al. [44] synthesized SiCN materials by pyrolyzing polyethyleneimine at 600-1500 \({}^{\circ}\)C. Compared to samples obtained at 600-800 \({}^{\circ}\)C (containing organic groups) and 1400-1500 \({}^{\circ}\)C (containing crystalline SiC), those produced between 1000-1300 \({}^{\circ}\)C, which incorporate free carbon, exhibit significantly higher charge-discharge capacities as anodes. The diminished capacity observed at \(\geq\)1500 \({}^{\circ}\)C is attributed to the formation of electrochemically inactive SiC phases [45; 46]. [PERSON] et al. [47; 48] highlighted that selecting the optimal calcination temperature involves balancing its impact on hysteresis, rate capability, charge transfer resistance, stability, and specific capacity.