DOI: 10.57760/sciencedb.21073
title: Experimental data on the properties of advanced hybrid binder and silicon anode.
title: Experimental data on the properties of advanced hybrid binder and silicon anode.

description: While silicon anodes offer transformative energy density for lithium-ion batteries, their large volume changes during cycling critically challenge binder systems. Current dynamic hydrogen-bonding binders suffer from compromised mechanical robustness and limited stress dissipation in high-power applications. We present an alginate-tannic acid (Alg-TA) hybrid binder that synergistically integrates dynamic H-bonding reversibility with multidimensional network reinforcement. The Alg-TA system establishes adaptive interfacial interactions with micron-sized silicon dendrites (SD-OH, ~15 µm), creating a self-healing matrix that redistributes mechanical stress through its hierarchical hydrogen-bonded architecture. Finite element simulations quantitatively demonstrate the binder's exceptional stress dissipation capability. The optimized electrode delivers remarkable cycling stability (retained a capacity of 1484.76 mA h g⁻¹ after 400 cycles at 4 A g⁻¹, with 80.2% capacity retention). This work provides fundamental insights into designing dynamic binder networks that reconcile mechanical integrity with electrochemical resilience, establishing a practical pathway for silicon anode implementation in next-generation high-energy batteries.CharacterizationX-ray diffraction (XRD) analysis of the phase composition and crystal structure was performed using a Bruker D8 Advance instrument. Fourier transform infrared (FTIR) spectroscopy was conducted on a Thermo Scientific Nicolet iS20 instrument to analyze the chemical bonds and functional groups of the samples. X-ray photoelectron spectroscopy (XPS) measurements were carried out using a Thermo Scientific K-Alpha instrument. The mechanical properties of the polymer binders and anodes were evaluated by tensile and 180° peel tests using an electronic universal testing machine. The viscosity of the binder samples was measured using an SNB-2 digital viscometer. Thermogravimetric analysis (TGA) was performed on a STA-8000 instrument, with a heating rate of 10 °C/min in the temperature range of 30-800 °C. The glass transition temperature (Tg) of the binder was measured using a Differential Scanning Calorimeter (DSC), and the testing conditions were the same as those used in the TGA analysis. Scanning electron microscopy (SEM) imaging of the samples and anodes was conducted on a ZEISS Sigma 300 instrument. Transmission electron microscopy (TEM) was performed using a JEOL JEM-F200 instrument. The specific surface area and pore size of the samples were measured using a Micromeritics ASAP2460 nitrogen adsorption-desorption instrument. The wettability of anodes was evaluated by contact angle measurements using a Contec TX500 TM rotational drop interfacial tensiometer.Electrochemical MeasurementsThe button cell was assembled in a glove box filled with a high-purity argon atmosphere. For the half-cell, the positive electrode consisted of the prepared silicon electrode, and the negative electrode was a 16 mm diameter lithium metal disc. Celgard 2325 served as the separator, while the electrolyte was composed of 1 M LiPF6 in a 1:1 volume ratio of ethylene carbonate (EC) and diethyl carbonate (DEC), incorporating 10 vol% fluoroethylene carbonate (FEC) as an additive. Before all tests, the batteries are left to rest at 30 °C for 24 h. The galvanostatic charge-discharge (GCD) and cyclic voltammetry (CV) tests were conducted at 30 °C within a voltage range of 0.01 V to 2.00 V using the Neware CT-4008 battery testing system and CHI760E electrochemical workstation, respectively. Electrochemical impedance spectroscopy (EIS) was also performed on the CHI760E, with a frequency range of 10⁻² to 10⁵ Hz and an amplitude of 5 mV. Galvanostatic intermittent titration technique (GITT) tests were carried out using the Neware CT-4008 system after three activation cycles at 0.2 A g⁻¹, starting with a current pulse time of 10 minutes, followed by a 1-hour relaxation period.SimulationThe finite element simulation was conducted using COMSOL Multiphysics 6.2 establishing an electrochemical-solid mechanics multiphysics model. To simulate the distribution of silicon particles in the conductive agent and binder composite material, a random distribution model was adopted. In this model, active silicon particles are randomly distributed in the carbon gel phase composed of the conductive agent and binder, forming a typical two-phase composite material structure. This model is used to evaluate the stress effects between silicon particles and the conductive polymer network during the lithiation process, thus predicting the mechanical behavior of the anodes. Additionally, representative volume elements (RVEs) were designed to simulate typical micro-regions within the anodes. Also, a random sequential adsorption algorithm was employed, where silicon particles were adsorbed into the volume element in a specific order, thereby constructing the composite material structure. Finally, simulation analysis was conducted based on physical parameters of silicon and its various alloy states, which were obtained from first-principles calculations.
description: While silicon anodes offer transformative energy density for lithium-ion batteries, their large volume changes during cycling critically challenge binder systems. Current dynamic hydrogen-bonding binders suffer from compromised mechanical robustness and limited stress dissipation in high-power applications. We present an alginate-tannic acid (Alg-TA) hybrid binder that synergistically integrates dynamic H-bonding reversibility with multidimensional network reinforcement. The Alg-TA system establishes adaptive interfacial interactions with micron-sized silicon dendrites (SD-OH, ~15 µm), creating a self-healing matrix that redistributes mechanical stress through its hierarchical hydrogen-bonded architecture. Finite element simulations quantitatively demonstrate the binder's exceptional stress dissipation capability. The optimized electrode delivers remarkable cycling stability (retained a capacity of 1484.76 mA h g⁻¹ after 400 cycles at 4 A g⁻¹, with 80.2% capacity retention). This work provides fundamental insights into designing dynamic binder networks that reconcile mechanical integrity with electrochemical resilience, establishing a practical pathway for silicon anode implementation in next-generation high-energy batteries.CharacterizationX-ray diffraction (XRD) analysis of the phase composition and crystal structure was performed using a Bruker D8 Advance instrument. Fourier transform infrared (FTIR) spectroscopy was conducted on a Thermo Scientific Nicolet iS20 instrument to analyze the chemical bonds and functional groups of the samples. X-ray photoelectron spectroscopy (XPS) measurements were carried out using a Thermo Scientific K-Alpha instrument. The mechanical properties of the polymer binders and anodes were evaluated by tensile and 180° peel tests using an electronic universal testing machine. The viscosity of the binder samples was measured using an SNB-2 digital viscometer. Thermogravimetric analysis (TGA) was performed on a STA-8000 instrument, with a heating rate of 10 °C/min in the temperature range of 30-800 °C. The glass transition temperature (Tg) of the binder was measured using a Differential Scanning Calorimeter (DSC), and the testing conditions were the same as those used in the TGA analysis. Scanning electron microscopy (SEM) imaging of the samples and anodes was conducted on a ZEISS Sigma 300 instrument. Transmission electron microscopy (TEM) was performed using a JEOL JEM-F200 instrument. The specific surface area and pore size of the samples were measured using a Micromeritics ASAP2460 nitrogen adsorption-desorption instrument. The wettability of anodes was evaluated by contact angle measurements using a Contec TX500 TM rotational drop interfacial tensiometer.Electrochemical MeasurementsThe button cell was assembled in a glove box filled with a high-purity argon atmosphere. For the half-cell, the positive electrode consisted of the prepared silicon electrode, and the negative electrode was a 16 mm diameter lithium metal disc. Celgard 2325 served as the separator, while the electrolyte was composed of 1 M LiPF6 in a 1:1 volume ratio of ethylene carbonate (EC) and diethyl carbonate (DEC), incorporating 10 vol% fluoroethylene carbonate (FEC) as an additive. Before all tests, the batteries are left to rest at 30 °C for 24 h. The galvanostatic charge-discharge (GCD) and cyclic voltammetry (CV) tests were conducted at 30 °C within a voltage range of 0.01 V to 2.00 V using the Neware CT-4008 battery testing system and CHI760E electrochemical workstation, respectively. Electrochemical impedance spectroscopy (EIS) was also performed on the CHI760E, with a frequency range of 10⁻² to 10⁵ Hz and an amplitude of 5 mV. Galvanostatic intermittent titration technique (GITT) tests were carried out using the Neware CT-4008 system after three activation cycles at 0.2 A g⁻¹, starting with a current pulse time of 10 minutes, followed by a 1-hour relaxation period.SimulationThe finite element simulation was conducted using COMSOL Multiphysics 6.2 establishing an electrochemical-solid mechanics multiphysics model. To simulate the distribution of silicon particles in the conductive agent and binder composite material, a random distribution model was adopted. In this model, active silicon particles are randomly distributed in the carbon gel phase composed of the conductive agent and binder, forming a typical two-phase composite material structure. This model is used to evaluate the stress effects between silicon particles and the conductive polymer network during the lithiation process, thus predicting the mechanical behavior of the anodes. Additionally, representative volume elements (RVEs) were designed to simulate typical micro-regions within the anodes. Also, a random sequential adsorption algorithm was employed, where silicon particles were adsorbed into the volume element in a specific order, thereby constructing the composite material structure. Finally, simulation analysis was conducted based on physical parameters of silicon and its various alloy states, which were obtained from first-principles calculations.