An easy and scalable synthetic route was proposed for synthesis of a high-energy stable anode material composed of carbon-coated Si nanoparticles (NPs, 80 nm) confined in a three-dimensional (3D) network-structured conductive carbon nanotube (CNT) matrix (Si/CNT@C). The Si/CNT@C composite was fabricated via in situ polymerization of resorcinol formaldehyde (RF) resin in the co-existence of Si NPs and CNTs, followed by carbonization at 700 °C. The RF resin-derived carbon shell (~10 nm) was wrapped on the Si NPs and CNTs surface, welding the Si NPs to the sidewall of the interconnected CNTs matrix to avoid Si NP agglomeration. The unique 3D architecture provides a highway for Li⁺ ion diffusion and electron transportation to allow the fast lithiation/delithiation of the Si NPs; buffers the volume fluctuation of Si NPs; and stabilizes solid–electrolyte interphase film. As expected, the obtained Si/CNT@C hybrid exhibited excellent lithium storage performances. An initial discharge capacity of 1925 mAh g⁻¹ was achieved at 0.1 A g⁻¹ and retained as 1106 mAh g⁻¹ after 200 cycles at 0.1 A g⁻¹. The reversible capacity was retained at 827 mAh g⁻¹ when the current density was increased to 1 A g⁻¹. The Si/CNT@C possessed a high Si content of 62.8 wt%, facilitating its commercial application. Accordingly, this work provides a promising exploration of Si-based anode materials for high-energy stable lithium-ion batteries.

A multistage architecture with molybdenum nitride and oxide quantum dots (MON-QDs) uniformly grown on nitrogen-doped graphene (MON-QD/NG) is prepared by a facile and green hydrothermal route followed by a one-step calcination process for lithium ion batteries (LIBs). Characterization tests show that the MON-QDs with diameters of 1–3 nm are homogeneously anchored on or intercalated between graphene sheets. The molybdenum nitride exists in the form of crystalline Mo₂N (face-centered cubic), while molybdenum oxide exists in the form of amorphous MoO₂ in the obtained composite. Electrochemical tests show that the MON-QD/NG calcinated at 600 °C has an excellent lithium storage performance with an initial discharge capacity of about 1753.3 mAh g⁻¹ and a stable reversible capacity of 958.9 mAh g⁻¹ at current density of 0.1 A g⁻¹ as well as long-term cycling stability at high current density of 5 A g⁻¹. This is due to the multistage architecture, which can provide plenty of active sites, buffer volume changes of electrode and enhance electrical conductivity as well as the synergistic effect between Mo₂N and MoO₂.

A composite electrode of carbon nanotube CNT@Mn₃O₄ nanocable was successfully synthesized via direct electrophoretic deposition onto a copper foil, followed by calcination. By uniformly depositing Mn₃O₄ nanoparticles on CNTs, a nanocable structure of CNT@Mn₃O₄ can be formed, where the CNT acts as a “highway” for electrons and ions to facilitate fast transportation. Moreover, capacitive energy storage processes play a crucial role in lithium (Li) storage, especially during high scan rates. The significant contribution of capacitance is highly advantageous for the rapid transfer of Li⁺ ions, which ultimately results in an improved reversible capacity and prolonged cycle stability of the battery. A high specific capacity of 1367 mAh g⁻¹ was maintained over 300 charge–discharge cycles at a current density of 1 A g⁻¹, indicating excellent capacity retention and an extended cycle life. Furthermore, the synthesis process was facile and cost-effective, obviating the need for complex procedures such as mixing and pasting. Additionally, no binder was required, thereby enhancing battery quality efficiency.