## 1 Introduction  
Next generation high-capacity electrode materials are needed to meet the demands of the explosion of electricity-fueled forms of transportation [1; 2; 3]. Graphite, the commercial anode material, cannot completely satisfy the requirements of electric vehicles due to its relatively low theoretical specific capacity. To overcome this problem, numerous researchers have focused on silicon-based anode materials because of its high theoretical specific capacity and relatively low charge/discharge voltage. Among them, silica (SiO\({}_{2}\)), the main institutions of sand and quartz, is generally considered to be a promising candidate [4; 5; 6; 7]. Silica is easier to prepare and is much more economical than silicon, while also stores a large quantity of lithium and has a relatively low potential platform. However, bulk-SiO\({}_{2}\) is generally conformed to be lithium inactive due to instinctive insulation [8; 9; 10; 11]. Therefore, considerable efforts have been devoted to various nanostructures, such as hollow nano-spheres [12], nano-films [8; 11], nano-cubes [13], nanotubes [14] and nano-belts [15]. There is no denying that nano-structures can facilitate the diffusion of electron and lithium ion effectively. However, nano-structuring also has its limitations. Its higher specific surface area consumes the more electrolyte to form solid electrolyte interface (SEI), which results in lower Coulombic efficiency (CE) and capacity fading [16]. In addition, nano-structured materials usually have a low tap density, leading to a low volumetric capacity and a thick electrode at high mass loading [16; 17]. As a result, maintaining the electrical and ionic pathways during cycling is difficult. Furthermore, nano-structuring usually requires a multi-step and advanced preparation process, leading to a higher cost. More seriously, silica can form a great deal of irreversible lithium silicates and Li\({}_{2}\)O during the first lithiation cycle. This process consumes an excess amount of cathode materials [6; 7; 8; 13; 18; 19], which significantly reduces the total energy density of full-cells, thereby preventing their practical applications. In order to tackle this issue, researchers have proposed prelithiation of the electrode material, which directly compensates for the irreversible loss of lithium during the first cycle [20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37]. For example, [PERSON] developed an electrochemical lithiation method to preload lithium in the Si and SiO\({}_{2}\) materials, which required the fabrication of a temporary cell and an inert atmosphere [35]. Recently, [PERSON]'s group developed thermal alloying silicon nanoparticles with molten lithium metal to obtain crystalline Li\({}_{x}\)Si with good crystallinity and acceptable dry stability [31; 32]. Here, we applied the thermal alloying method to the silica particles, achieved the prelithiated composites (Li\({}_{x}\)Si/Li\({}_{2}\)O), and finally studied their electrochemical properties. Such composites have multiple advantages: (1) prelithiation effectively improves the electrical conductivity of silica, making it easier to function as an anode with high capacity and cycle stability; (2) Li\({}_{x}\)Si/Li\({}_{2}\)O composites can address the low initial Coulombic efficiency (ICE) issue of Si-based anodes, which is a huge challenge for practical application; (3) Li\({}_{x}\)Si/Li\({}_{2}\)O composites alloy can serve as a promising anode containing lithium to pair with high-capacity lithium-free cathodes such as S for next-generation lithium-ion batteries. We have chosen different SiO\({}_{2}\) particles with different sizes (6 nm, 20 nm, 300 nm and 3 \(\upmu\)m), and systematically studied their electrochemical performance. All prelithiated Li\({}_{x}\)Si/Li\({}_{2}\)O composites exhibit better performance than that of pristine SiO\({}_{2}\) particles.