Lithium-ion batteries (LIBs) play a key role in this field. However, it remains a great challenge to design LIBs with ever higher capacity and stable cycle life. Limited by the theoretical capacity of commonly used anodes (e.g., graphite: 372 mAh•g -1 ), is is difficult to meet the increasing application requirements. Silicon-based anode materials attract widespread research interest due to silicon's high theoretical capacity (3579 mAh•g -1 ), which is much higher than commercialized graphite anodes. The main obstacle of implementing silicon anodes into applications is the volume expansion during the charging and discharging processes (e.g. about 400%). This causes serious problems in anodes, like pulverization of Si particles, high interfacial resistance, and continuous liquid electrolyte consumption caused by repeated SEI formation. The low Coulombic efficiency (CE) and SEI accumulation gradually increase the interfacial resistance, leading to performance decay. Also, the low conductivity of Si particles affects the battery performance. To suppress the volume expansion and overcome this restriction, various strategies have been attempted. Nanosized Si, like silicon nanotubes , silicon nanoparticles and nanowires , have been shown to effectively accommodate the volume change during cycling. Liu et al. obtained nanostructured silicon particles from rice husks via thermally decomposition and magnesiothermic reduction treatment, which delivered high reversible capacity (2,790 mAh•g -1 ) and long cycle life (86% capacity retention over 300 cycles at 2.1 A•g -1 ). Using rice husks as the raw material provides a green and low-cost strategy to synthesize silicon on a large scale. To improve the electrical conductivity of silicon anodes, various Si-containing composite structures have been exhibited to further improve the performance of these anodes , which provide buffer regions for volume expansion by surface modification of silicon or embedding silicon particles inside different carbon materials, including carbon nanotubes and graphene . Also, these methods intended to reduce the direct exposure of Si with liquid electrolyte to minimize side reactions, improve electrical conductivity of anodes and further increase cycling life. However, the carbon coating layer alone has less of an interfacial interaction with the silicon surface and is easily cracked and higher contents of carbon could reduce the specific capacity per gram. To solve this problem, combinations of carbon and silicon oxide (SiOx, 0<x<2) has been designed and prepared with different methods. SiOx is a trade-off alternative of Si anodes, which has relatively lower capacity (2200-3580 mAh•g -1 ) but longer cycling life. The lithium silicates and Li2O are formed during the initial lithiation cycle of SiOx, which deposits on the outer layer of Si particles to get stable SEI layer and buffer the volume expansion to some degree. Incorporating SiOx with Si/C composite materials, the obtained composites can improve cycling stability without sacrificing too much capacity. Hernandha et al. coated Si particles with a SiOx layer via interaction with supercritical CO2 and deposited a carbon film on the outer layer using glucose as the precursor. The obtained anodes showed high specific capacity of 918 mAh•g -1 at 5 A•g -1 and remained high integrity after continuous cycling. Halim et al. synthesized a SiOx@C matrix from the thermal conversion of polysiloxanes, which is also called silicon oxycarbide (SiOC). The structure of SiOx@C is similar to SiOx and the doped free carbon inside particles could offer the particles with better electronic conductivity, better rigidity and cycling performance. In order to take advantage of both Si and SiOx@C, embedding Si in a matrix of SiOx@C should be a feasible and reliable strategy. Herein, we present a "nano-skeleton" structured Si-SiOx@C composite anode featuring an improved mechanical buffer and electrical contact between nanoparticles upon cycling, enhancing the battery performance. For material fabrication, due to the interaction between glutaraldehyde and polydopamine layers in the precursor solution, the fast and homogenous molecular crosslinking reaction could instantly form SiOx@C precursor around polydopamine-wrapped silicon (PDA-Si) with conductive multi-wall carbon nanotubes (CNTs) as the skeleton once (3-aminopropyl) trimethoxysilane (APTMS) was added dropwise. After carbonization, the CNTs were tightly twined and filled between the PDA-Si and SiOx@C nano particles. Due to the particle-stacked structure, the curled CNTs can provide flexible springs to ensure reversible buffers for volume expansion during cycling. Meanwhile, this buffering "nano-skeleton" structure can provide adequate conductive pathways between carbon doped SiOx@C and carbonwrapped Si derived from PDA-Si. Promisingly, in this CNT-supported Si-SiOx@C structure (named as Si-SiOx@C-1.25, Si-SiOx@C-2.5 and Si-SiOx@C-5, respectively), the continuous electron transfer and relief of internal stress caused by Si during the lithiation and delithiation processes could be realized simultaneously. As a result, the nano-skeleton supported Si-SiOx@C-1.25 anodes deliver a high capacity (918 mAh•g - 1 at 200 mA•g -1 ) and high-capacity retention (74% after 300 cycles) with relieved volume expansion (71.4%). Confirmed by in-operando XRD, Raman and XPS of fully lithiated anodes, the stable and dense SEI layers are formed on the surface of CNTsupported nano-skeleton structure, providing high cycling stability. Paired with NMC111, the specific capacity of the full cell can be stable at about 70 mAh•g -1 after 500 cycles at 100 mAh•g -1 . Followed by drying in oven for 8 h, the final product is abbreviated as PDA-Si. 2.3 Synthesis of Si-SiOx@C-CNTs CNTs and PDA-Si (150 mg) were dispersed in GA solution (1%, 40 mL) via bath sonication for 30 min and stirring overnight. Then 0.746 ml APTMS was added dropwise into the above suspension, followed by stirring for 30 min. After filtration and washing, Si-SiOx@C-CNTs are obtained by freeze drying and carbonization (700 °C, 2 h, Ar atmosphere). Based on the added amount of CNT (0, 4.6, 9.2 and 18.4 mg), the carbonized products (Si-SiOx@Cs) are abbreviated as Si-SiOx@C, Si-SiOx@C-1.25, Si-SiOx@C-2.5 and Si-SiOx@C-5, respectively, while the uncarbonized samples (P-Si-SiOx@Cs) are abbreviated as P-Si-SiOx@C, P-Si-SiOx@C-1.25, P-Si-SiOx@C-2.5 and P-Si-SiOx@C-5, respectively. Also, the carbonized particle from PDA-Si is abbreviated as C-PDA-Si. V, 0.8V, 0.5 V, 0.3 V, 0.2 V, 0.1 V and 0.005 V.