Silicon Particles Research Articles

Developing bio-carbon matrices for the encapsulation of silicon nanoparticles for high-performance lithium-ion battery anode materials.

Silicon (Si) is considered to be one of the most promising anode materials for next-generation lithium-ion batteries. However, the practical application of Si-based anodes is mainly hindered by the low intrinsic conductivity of Si and the large volume change upon lithiation/de-lithiation. Here, we prepared a composite material consisting of Si nanoparticles (NPs) and coconut silk bio-carbon (CSC) skeleton. The porous carbon skeleton derived from coconut silk with natural through-holes and ample micropores, which was used as the carrier of Si NPs. The continuous through-holes and well-distributed oxygen-containing functional groups of the CSC provided sufficient space and adsorption active sites for Si NPs, what's more, the good dispersion of Si NPs increased their contact with the surrounding carbon materials, which was conducive to electron transport. Meanwhile, the pore structure provided buffer space for the volume expansion of Si. The rich oxygen-containing functional groups can form a certain chemical force with silicon particles, and further stabilize the nano silicon particles. Hence, the CSC/Si electrode revealed an excellent capacity retention of 82.8% at 1 A g-1 after 100 cycles. This study provides a simple universal high-throughput method to obtain anode materials with outstanding electrochemical properties and promotes the further development of Si/C composites.

Elucidating the Morphology of Partially Lithiated Microscale Silicon Particles using Transmission Electron Microscopy

Abstract Partial lithiation of silicon active materials for lithium-ion batteries recently gained attention as a promising mitigation strategy for the degradation phenomena associated with the severe volume expansion upon the lithiation, particularly in the case of large, microscale silicon particles. It was suggested that this is caused by the formation of a stabilizing core-shell-like particle structure in the first cycles, consisting of a crystalline core and amorphous silicon shell. In this study, we investigated the microstructure of partially lithiated microscale silicon particles using transmission electron microscopy (TEM). When observed via TEM, the contrast difference in amorphous and crystalline silicon is utilized to reveal previously lithiated areas inside the silicon microparticle. We investigated the influence of lower cutoff potentials and amorphization progress in half-cells. We also examined the changes over prolonged cycling in full-cells with an NCA cathode after 12 and 243 cycles. Silicon particle pulverization was not observed for any sample, even though we found that substantial parts of the particles' insides had been lithiated. We suggest that the diffusion of Li along grain boundaries and stacking faults plays an essential part in the amorphization and cycling of microscale Si particles but does not lead to their cracking or pulverization.

Slow Voltage Relaxation of Silicon Nanoparticles with a Chemo-Mechanical Core-Shell Model.

Silicon presents itself as a high-capacity anode material for lithium-ion batteries with a promising future. The high ability for lithiation comes along with massive volume changes and a problematic voltage hysteresis, causing reduced efficiency, detrimental heat generation, and a complicated state-of-charge estimation. During slow cycling, amorphous silicon nanoparticles show a larger voltage hysteresis than after relaxation periods. Interestingly, the voltage relaxes for at least several days, which has not been physically explained so far. We apply a chemo-mechanical continuum model in a core-shell geometry interpreted as a silicon particle covered by the solid-electrolyte interphase to account for the hysteresis phenomena. The silicon core (de)lithiates during every cycle while the covering shell is chemically inactive. The visco-elastoplastic behavior of the shell explains the voltage hysteresis during cycling and after relaxation. We identify a logarithmic voltage relaxation, which fits with the established Garofalo law for viscosity. Our chemo-mechanical model describes the observed voltage hysteresis phenomena and outperforms the empirical Plett model. In addition to our full model, we present a reduced model to allow for easy voltage profile estimations. The presented results support the mechanical explanation of the silicon voltage hysteresis with a core-shell model and encourage further efforts into the investigation of the silicon anode mechanics.

Multiresponse optimization applied to friction-stir processing to enhance wear and corrosion performance in Al–Si alloys

In this study, friction stir processing (FSP) parameters were optimized using the response surface method (RSM) to enhance hardness, reduce the friction coefficient and minimize the corrosion rate in cast Al12Si and Al14Si alloys. The FSP tool, made of AISI H13 tool steel, features a concave shoulder and conical pin designed to induce severe plastic deformation. Microstructural analysis was performed via optical microscopy and SEM–EDS, and the particle size and distribution were assessed via ImageJ software. Microhardness profiles were measured across the Nugget, TMAZ, HAZ, and substrate zones. The corrosion resistance was evaluated using an AutoLab potentiostat/galvanostat following ASTM G59-97 standards, whereas the wear performance was assessed using a reciprocating linear tribometer (ASTM G133). FSP led to the fragmentation and uniform distribution of silicon and Fe-rich intermetallic phases within the aluminum matrix. The multiresponse optimization identified the optimal FSP parameters for Al12Si alloys at a tool rotation speed of 1100 rpm and a travel speed of 16 mm/min. Under these conditions, the Al12Si samples presented the highest microhardness (93 Hv), significant fragmentation of silicon particles (2.82 μm) and Fe-rich intermetallic phases (2.07 μm), reduced friction coefficient (0.60) and low corrosion rate (1.28 × 10⁻4 mm/y). The proposed model offers a reliable method to optimize FSP, leading to aluminum surfaces with superior microstructure, hardness, wear resistance and corrosion resistance.

Microstructure evaluation of Si-modified aluminide coatings on IN625 deposited by slurry aluminizing process

Si-modified aluminide coatings are promising for improving oxidation and corrosion resistance in superalloys at high temperatures. This study investigated the effect of different silicon levels in the aluminizing slurry on the morphology and structure of Si-modified aluminide coatings on IN625. This process involved spraying a slurry of aluminum and silicon particles in an aqueous PVA solution onto IN625 samples, followed by heat treatment under controlled conditions - two atmospheres (air and argon) and two heating ramps (regular and flash). Surface morphologies, cross-sectional structures, elemental compositions, and phase formations were analyzed using FE-SEM, SEM, EDS, and XRD methods, while DTA analysis assessed AlSi alloy formation during heating. The results showed that higher silicon content in the slurry increased silicon incorporation in the coatings but did not reduce aluminum activity enough to deposit a low-activity aluminide coating. The inert atmosphere (argon) and flash heating promoted the co-deposition of Si and Al, resulting in Cr and Mo silicide-enriched outer layers in some samples. The aluminum content in all slurries was sufficient for consistent β-NiAl formation across different silicon levels. The average silicon content in coatings ranged from 5 to 15 wt% and depended on the slurry composition and heat treatment conditions. The Al30Si slurry produced the thickest coatings (~90 μm), with further increases in Si leading to reduced thickness. This study suggests that slurry aluminizing can be optimized to control silicon incorporation, depositing Si-modified aluminide coatings for durable, high-performance applications.

Improving the Performance of Silicon-Based Negative Electrodes in All-Solid-State Batteries by In Situ Coating with Lithium Polyacrylate Polymers.

In all-solid-state batteries (ASSBs), silicon-based negative electrodes have the advantages of high theoretical specific capacity, low lithiation potential, and lower susceptibility to lithium dendrites. However, their significant volume variation presents persistent interfacial challenges. A promising solution lies in finding a material that combines ionic-electronic conductivity, stable physicochemical properties, and adhesive characteristics. Poly(acrylic acid) (PAA) is widely used in liquid-state batteries due to its superior properties compared to polyvinylidene fluoride (PVDF). In this study, silicon particles were coated with varying concentrations of PAA and LiPAA using an in situ liquid-phase coating method to form electrode sheets. The experimental and analytical results revealed significant trends in the impact of different additive concentrations on the electrochemical performance, with 1.0 wt % LiPAA showing notable improvements in Coulombic efficiency, rate capability, and long-term cycling stability. The assembled all-solid-state batteries exhibited a high initial discharge capacity of 3200 mAh/g, with a capacity retention of 81.9% after 300 cycles at 0.3 C, and a stable discharge capacity of 1300 mAh/g at a 2 C rate. A rapid and efficient in situ liquid-phase coating method for LiPAA was developed and confirmed through FTIR, XRD, and TEM characterization. SEM and XPS analyses demonstrated that LiPAA encapsulation effectively alleviates interfacial issues. This study demonstrated for the first time that an appropriate amount of LiPAA coating on silicon particles can mitigate the interfacial challenges caused by the volume expansion of silicon-based negative electrodes. These findings improve electrochemical performance and promote the application of silicon-based negative electrodes in all-solid-state batteries.

Elimination of dead layer in silicon particle detectors via induced electric field based charge collection

The front surface of semiconductor particle detectors typically contains undepleted recombination active regions that the impinging particles pass through before reaching the sensitive area of the device. These so-called dead layers pose a fundamental limitation for achievable energy resolutions and are unavoidable in externally doped pn-junction detectors. Here, we fabricate a silicon particle detector using an alternative method for charge collection that extends the sensitive region to the front surface of the device and minimizes the dead layer. The junction is realized by inducing an electric field at the surface of the detector using a charged thin film. Such an approach has previously been implemented in photodiodes, which have demonstrated effective collection of charge carriers from the very surface of the devices. Our detector displays low leakage currents and recombination, which allow efficient charge collection throughout the device, as demonstrated by excellent internal quantum efficiency of the device. The detector is further characterized using detection of alpha particles as a case example. We achieve 20 keV energy resolutions that are, already without extensive device optimization, on the same level with commercial externally doped silicon particle detectors. Notably, the design shows promise for detection of shallow penetrating charged particles, which is very sensitive to dead layers.

Progress in the application of silicon-based materials in lithium-ion batteries anodes

From the battery that powers the remote control to the battery that powers electric cars, lithium-ion batteries (LIBs) are a crucial component of contemporary energy storage. The large theoretical capacity of silicon anodes provides significant benefits inside LIBs. However, the main issue with the conventional silicon bulk anode is its considerable volume expansion, which forms an unstable Solid Electrolyte Interface (SEI) layer during the charge and discharge process and severely reduces battery performance and lifespan. Therefore, to solve these issues, researchers have explored multiple improved silicon anodes, three of which are mentioned in this essay. Firstly, the researchers delve into the usage of nanotechnology. When manipulating silicon particles at the nano-scale, the nano-silicon can mitigate the volume expansion, improving the reaction kinetics. Then, a composite of carbon and silicon is proposed, combining silicon's high capacitance and carbon's high conductivity. After that is the silicon-metal composite, which utilizes metals' mechanical strength and conductivity to stabilize Si anodes further and improve thermal stability. Overall, the significance of this study lies in the exploration of the application of silicon anodes in LIBs, highlighting the potential of these composite materials and advanced technology, which may help guide the future exploration of better silicon anodes.

The Exposure Height of Silicon Particle with Round Edges Effect on the Tribological Property of Al-Si Alloy Cylinder Liner

In order to improve the wear resistance of Al-Si alloy cylinder liners, surface treatment is usually used. The Al-Si alloy cylinder liner samples were prepared by mechanical grinding and laser finishing. The mechanical grinding samples were carried out by the independent design and development of a grinding machine. The laser finishing samples were laser-heated by a CO2 continuous transverse-flow laser. Both of the two surface treatments could provide the surfaces of protruding silicon particles with round edges to improve the wear resistance. However, in the exposure height of silicon particles with round edges, the study was lacking. The exposure height of silicon particles is important to the tribological properties of the Al-Si alloy cylinder liner, and should be analyzed in detail. The wear tests were completed by a contraposition reciprocating wear test rig under lubrication. It was found that when the silicon particles were exposed on the surface of the Al-Si alloy cylinder liner sample by 1.2 μm, the mechanical grinding samples and laser finishing samples all exhibited minimum friction coefficients and weight losses. This paper confirms that a suitable exposure height of silicon particles would reduce the probability of adhesion wear and abrasive wear of Al-Si alloy cylinder liners and increase the lubrication. It presents an excellent tribological property. However, when the exposure height of silicon particles is too high, the silicon particle is easily prone to plastic deformation or even falls off during the friction process due to the high stress and larger plastic contact index.

Poly(Acrylic Acid)-Based Polymer Binders for High-Performance Lithium-Ion Batteries: From Structure to Properties.

Poly(acrylic acid) (PAA) and its derivatives have emerged as promising candidates for enhancing the electrochemical performance of lithium-ion batteries (LIBs) as binder materials. Recent research has focused on evaluating their ability to improve adhesion with silicon (Si) particles and facilitate ion transport while maintaining electrode integrity. Various strategies, including mixing modifications and copolymerization methods, are highlighted and the structural and physicochemical properties of these binders are examined. Additionally, the interaction mechanisms between PAA-based binders and active materials and their impact on key electrochemical properties such as initial Coulombic efficiency (ICE) and cycle stability are discussed. The findings underscore the efficacy of tailored PAA-based binders in enhancing the electrochemical properties of LIBs, offering insights into the design principles and practical implications for advanced battery materials. These advancements hold promise for developing high-performance lithium batteries capable of meeting future energy storage demands.

Formation of seaweed morphology and enhancing mechanical properties of an A356 alloy by directional solidification

In the present work, regular dendrite and seaweed pattern are produced by controlling the crystal orientation during directional solidification of an A356 aluminium alloy. These morphologies and growth orientation were investigated by electron backscatter diffraction (EBSD), and the results showed that the seaweed pattern mainly prevailed under the (100)[011] orientation. At the same time, the effects of seaweed pattern in the properties of A356 alloy were analysed by room temperature tensile test. It was found that the elongation and toughness of the samples reached 20 % and 36 J/m3, respectively, for the seaweed; 13 % and 24 J/m3, respectively, for the regular dendrites; and 8 % and 14 J/m3, respectively, for the cast ingot. Compared with the regular dendrite samples, the seaweed pattern obtained relatively excellent elongation and toughness. By using scanning electron microscopy (SEM), it is found that the distribution of eutectic silicon particles in seaweed morphology sample is more refined and uniform, which is the main reason for these enhancements.

Enhancing the combustion of silicon nanoparticles via plasma-assisted fluorocarbon surface modification

Nanostructured silicon has great potential as an energetic material due to its high energy density, close to that of aluminum; however, its combustion kinetics are strongly affected by the presence of a native oxide layer. As the particle size is reduced, the material behavior is dominated by surface effects, highlighting the need for new approaches to fabricate silicon nanoparticles and precisely control their surface chemistry. Here, we describe the use of low-temperature plasma to nucleate and grow < 10 nm silicon particles. The resulting aerosol is passed through a second plasma reactor, to which a fluorocarbon monomer is supplied. The second plasma initiates the growth of a polymeric shell onto the silicon particles, resulting in a highly conformal coating. Chemical analysis confirms that the polymer shell is compositionally similar to polyvinylidene fluoride (PVDF). We find that the fluorocarbon shell acts as an artificial passivation layer that significantly delays the onset of oxidation in air. In addition, the direct contact between the fluorocarbon shell and silicon core lowers the ignition temperature compared to the physical mixtures of silicon nanoparticles and PVDF. It leads to a higher pressurization rate and a lower combustion time when tested in a combustion cell. This is consistent with the combustion process being initiated by the exothermic interfacial reactions between the silicon core and the fluorocarbon shell. Mass spectroscopy confirms this hypothesis because silicon fluoride is produced only for the core–shell structure, and not for a physical mixture of silicon and PVDF. This study provides an example of a new processing technique capable of controlling the interfacial chemistry of small nanoparticles with beneficial effects on their combustion.

Bio-Inspired Self-Healing Silicon Anodes: Harnessing Tea Polyphenols to Enhance Lithium-Ion Battery Performance.

This study introduces an anode material for lithium-ion batteries, achieved by integrating tea polyphenols (TP) with the widely utilized polyacrylic acid (PAA) binder. The composite material capitalizes on the intrinsic self-healing properties of TP, enhancing the anode's durability and adhesiveness without the need for additional organic synthesis. The incorporation of TP has been demonstrated to significantly elevate ionic conductivity and expedite lithium ion diffusion, thereby reducing interfacial resistance and decelerating the rate of capacity fade due to electrolyte decomposition and silicon particle expansion. Employing a comprehensive analytical toolkit, including Fourier transform infrared spectroscopy, thermogravimetric analysis, peel strength measurements, and density functional theory calculations, we elucidated the physicochemical properties of the Si@PAA-TP anode. The anode's electrochemical performance was systematically assessed through galvanostatic charge-discharge, cyclic voltammetry, and electrochemical impedance spectroscopy, with scanning electron microscopy providing insights into postcycling mechanical property alterations. This research advances a cost-effective, high-performance adhesive strategy for silicon anodes and contributes to the development.

Wear micromechanics, mechanisms and wear map of Al-12.6Si-0.25Fe-XMn alloy: The role of Al15(Mn,Fe)3Si2 intermetallic and microstructure modification

Abstract The study investigates the microstructural evolution and wear behaviour of Al-12.6Si-0.25Fe-xMn alloys (x = 0, 1, 2, and 3 wt.%) in dry sliding wear experiments. Manganese (Mn) considerably modifies the microstructure by modifying primary and eutectic silicon particles, changing Fe-rich intermetallic compounds, and increasing the overall wear resistance of Al-12.6Si-0.25Fe. The microstructural investigation demonstrates the production of Al15(Mn,Fe)3Si2 intermetallic phases, as well as a more uniform Si particle distribution. Wear experiments at varied loads (20 N, 40 N, and 60 N) show that Mn addition significantly reduces wear rates and specific wear rates, especially at lower loads. The findings highlight Mn's significance in increasing the hardness and wear resistance of Al-Si-Fe alloys, making them better suited to automotive applications.

Grain Structure Engineering in Screen-Printed Silver Flake-Based Inks for High-Temperature Printed Electronics Applications.

We extensively studied serigraphic screen-printed commercial silver flake inks loaded with silicon inclusions in order to achieve pinning at the grain boundaries. Based on grain size measurements using electron backscattered diffraction (EBSD), commercial silver ink with silicon microparticle content of 5 wt.% shows significant grain growth retardation compared to pristine silver ink, which stabilizes electrical conductivity up to 700 °C via a Zener pinning mechanism. The modified silicon-loaded silver ink experiences a two-times increase in grain size when heated up to 700 °C, compared to a seven-times increase for pristine silver ink. In turn, this enables operation temperatures significantly higher than the conventional operational window of microparticle-based silver inks, which are usually limited to 400 °C. Using isothermal exposures of 10 min up to 4 h, this phenomenon is observed at temperatures ranging from 250 °C to 900 °C. The electrical conductivity stability, grain size evolution and oxide contents were studied up to 4 h. The activation energy of silver ink with silicon inclusions is 54% lower than for pristine silver ink due to the pining effect, which retards grain growth via the Zener mechanism. Most importantly, the electrical resistivity remains stable up to 700 °C, which is more than twice the operation limit for off-the-shelf screen-printable silver flake inks. Hence, we demonstrate that adding controlled amounts of silicon particles to silver inks for grain structure engineering can open new vistas of possibilities for screen-printed metallic inks.

Maleic anhydride esterified potato starch as the binder in silicon nanoparticles anode for lithium-ion batteries

Potato starch is a natural carbohydrate binder. Starch has hydroxyl groups that can promote interaction with silicon particles using multifaceted hydrogen bonds. Maleic anhydride esterified potato starch can produce a binder that maintains the cycle stability of lithium-ion batteries. Fourier-transform infrared spectroscopy spectra show wavelengths of 1776 cm−1 and 1855 cm−1. Thermal gravimetric analysis curves decreased in weight percent by 80 % at 286 °C. Carbon-13 nuclear magnetic resonance spectra show high peaks at 3.37 ppm, 3.65 ppm, 4.56 ppm, 5.09 ppm, and 6.22 ppm. Scanning electron microscope images show that the morphological change in esterified starch was due to the increased length of starch and the maleic anhydride grafted onto the starch granules. The cyclic voltammetry curve shows that the reduction peak is around 0.16 V, and the oxidation peak is around 0.38 V and 0.56 V. Nyquist plots show a small half circle, indicating that the electrode's solid-electrolyte interphase layer is low. The cycling performance shows a capacity of 1950 mAh/g.

Nano-strategies for advancing oral drug delivery: Porous silicon particles and cyclodextrin encapsulation for enhanced dissolution of poorly soluble drugs

Development of novel active pharmaceutical ingredients (API) for oral use often face challenges due to low bioavailability. Nanoparticle-based drug delivery systems and cyclodextrin (CD) encapsulation offer promising solutions by enhancing API solubility or dissolution rates. Porous silicon nanoparticles have shown potential to encapsulate APIs in their amorphous form within the pores, improving their dissolution rates compared to crystalline counterparts. A novel synthesis approach, circumventing the expensive and tedious synthesis from Si wafer material, has been developed using centrifugal Chemical Vapor Deposition (cCVD). Herein, various cCVD Si particles were evaluated for their ability to enhance the dissolution rate of the model drugs celecoxib (CEL), phenytoin (PHT), griseofulvin (GRI), diclofenac (DCF) and naproxen (NAP). Our findings demonstrate increased dissolution rates of all tested APIs when formulated with cCVD Si particles, compared to free API in pH 7.4 or pH 2.0. Particle characteristics were largely retained after loading, and the solid state of the loaded APIs were evaluated using Differential Scanning Calorimetry (DSC). Dissolution kinetics were influenced by the particle properties, mass loading and API characteristics. Loading of CD-CEL, −GRI and −DCF complexes into the cCVD Si particles showed a potential for further enhanced dissolution rates, representing the first reported investigation of this combination. In conclusion, the cCVD Si particles are promising for improving the dissolution rate of poorly soluble drugs, potentially due to precipitation of amorphous or metastable forms. Further enhancements were observed upon loading CD-drug complexes, thereby offering promising strategies for optimizing drug bioavailability.

Construction of WO3 nanowires artificial solid electrolyte interphase on silicon nanoparticles with sea urchin like structure for improving silicon anode stability

Giant volumetric variation of silicon during repeat lithiation/delethiation process leads to structure failure of silicon-based anodes and thus their initial high capacitance is hard to be maintained under long-run cyclic charging/discharging. Construction porous structure silicon composites and formation of artificial solid electrolyte interphase (SEI) coating on silicon particles are two effective ways to improve stability of silicon-based anodes. In this work, above two strategies are combined to construct a composite of inorganic artificial SEI WO3 nanowires/Si nanoparticles with sea urchin like porous structure via simple hydrothermal method. The silicon nanoparticles act as seeds for around 70 nm average diameter WO3 nanowires formation in compared with that of WO3 nano-rods around 500 nm diameter without Si nanoparticle seeds. The WO3 nanowire artificial SEI coating is found to be effective in preventing SEI overgrowth and their network provides spaces for volumetric variation of silicon nanoparticles in the bulk anode matrix during cyclic test, leading to reversible charging/discharging of stable bulk anode in compared with pure silicon anode of fast capacitance decay. The gravimetric capacitance of optimized composite reaches 1410.6 mAh·g−1 and its capacity remains 1039 mAh·g−1 after 200 cycles.

Understanding the impact of porosity on Li-ion diffusion enhancement in micro-sized silicon particles for advanced batteries

Lithium-ion batteries (LIBs) require advanced and practical anode materials, such as porous silicon (PSi), which can meet these expectations due to their rapid Li-ion diffusion rates and structural relaxation. Several studies have focused on the structural design of PSi or its composites to improve Li-ion diffusion; however, no systematic and quantitative evaluations of the impact of porosity on Li-ion diffusion and battery performance have been reported. Therefore, to understand the impact of porosity on Li-ion diffusion, we developed micro-sized porous silicon (m-PSi) particles with various porosities via metal-assisted chemical etching (MACE) method using different concentrations of AgNO3 (0.02–0.08 M). Among the as-prepared samples, m-PSi-0.06 (prepared using 0.06 M AgNO3) with ∼70 % porosity achieved a maximum Li-ion diffusion rate of 2.35 × 10−9 cm2 s−1. This led to a high-rate capability, enhanced Li-ion storage, and better cyclic retention of 61.4 % compared to the non-porous micro-sized Si (m-Si) (5.8 %) sample at a current density of 0.1 A g−1. Furthermore, the optimal porosity of m-PSi-0.06 resulted in an impressive rate capability of 760 mAh g−1 at a high current density of 4 A g−1 with a recovery rate of 80 %. The improved efficiency of m-PSi-0.06 is attributed to its optimized mesoporosity, which ensures sufficient space for Li-ion storage and shortens the effective transmission path to accelerate Li-ion diffusion. Moreover, the mesopores provide a greater number of active sites for the reversible adsorption of Li ions, thereby improving the capacitive behavior of the anode. In contrast, the highly nanoporous m-PSi-0.08, with a pore diameter of 1–3 nm, impeded Li-ion movement and restricted diffusion. These results reveal that a high nano porosity hinders Li-ion diffusion, whereas an optimal mesoporosity ensures swift diffusion in m-PSi anodes. These insights could guide the design of Si-based anode materials for advanced LIBs.

Biological small molecule interface-modification fostering resilient interfacial chemistry for silicon-based anodes

Silicon-based materials, particularly at the microscale, are prone to rapid capacity fade due to substantial volume fluctuations during the charge-discharge cycles, significantly impeding their commercial viability. Constructing a stable solid electrolyte interface (SEI) is an effective means to improve the performances of silicon-based anodes. Here small biomolecules, tryptophan (Trp) and phytic acid (PA), are introduced as interface modifiers to optimize the interfacial chemistry of micron-silicon anodes. By engaging in the SEI formation process, these small biomolecules effectively regulate the chemical composition and mechanical properties of the formed SEI, fostering a more cohesive and durable interface. The simultaneous addition of PA and Trp has been observed to yield a synergistic effect, creating a tightly bonded and resilient SEI that confers markedly improved battery performances upon the co-modified micron silicon anodes. Density functional theory calculations reveal charge interactions between these small biomolecules and silicon particles, facilitating effective adsorption onto the silicon surface. Simultaneous adsorption of Trp and PA on silicon surface can significantly enhance adsorption strength, providing a compelling explanation for the observed synergistic effect of Trp and PA co-modification.