A5059298076- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Advanced Battery Technologies Research
- Semiconductor materials and interfaces
- Semiconductor materials and devices
- Supercapacitor Materials and Fabrication
- Force Microscopy Techniques and Applications
- Surface and Thin Film Phenomena
- Electron and X-Ray Spectroscopy Techniques
- Fuel Cells and Related Materials
- Advanced battery technologies research
- Metal Alloys Wear and Properties
- Advanced Electron Microscopy Techniques and Applications
- Microstructure and Mechanical Properties of Steels
- Anodic Oxide Films and Nanostructures
- Conducting polymers and applications
- Hydrogen embrittlement and corrosion behaviors in metals
- Electrical and Bioimpedance Tomography
National Renewable Energy Laboratory
2020-2024
Colorado School of Mines
2020-2024
A 74 wt% silicon composite electrode delivers 1000 cycles with 74% capacity retention against NMC811 cathodes and a cell stack energy density of 212 W h kg −1 in standard carbonate electrolyte two simple chemical process improvements.
Composite silicon-graphite (Si-Gr) anodes can improve battery energy density, due to Si's high gravimetric capacity, while mitigating mechanical degradation of the anode and solid-electrolyte interphase (SEI) caused by Si volumetric expansion. Optimizing these is challenging, in part difficulty characterizing SEI structure composition. In this work, we present multi-modal characterization on composite Si-Gr relate chemical composition functional properties. Discrepancies elemental...
We demonstrate that the addition of CO 2 to a standard 1.0 M LiPF 6 3:7 wt% ethylene carbonate:ethyl methyl carbonate electrolyte results in formation thinner insoluble solid interphase (SEI) is dominated by presence LiF. In contrast, cells without result thicker SEI layer containing more organic constituents. The incorporated dimethyl soluble part composed primarily polymeric poly(ethylene oxide) (PEO) on surface thin inorganic layer. This combination properties from provides an improved...
Carbon additives in lithium-ion battery electrodes are needed to provide electrical conductivity through the electrode but also can have a strong influence on morphology that dictates ion transport. For conversion-type electrodes, both electron and transport properties key parameters determining cycling performance. Understanding effect of carbon change is critical for rational design. In this work, we study impact 1-dimensional (1D) aspect ratio silicon nanoparticle-based composite...
700 °C is the optimal heat treatment temperature for pitch-coated silicon electrodes. Both amorphous carbon/pitch and are active materials but store Li + ions through different ion storage mechanisms contribute to overall performance.
Silicon (Si) is a promising anode material for high-energy-density lithium-ion batteries (LIBs), but its short calendar life and poor cycling performance prevent large-scale adoption. Introducing magnesium (Mg) salt into the electrolyte has been recently shown to form ternary Li–Mg–Si Zintl phase upon lithiation of Si improve performance. However, formation mechanism impact on solid interphase (SEI) are not yet well understood. Here, we demonstrate by Mg coating anode, where diffuses film...
Nanoparticle silicon–graphite composite electrodes are a viable way to advance the cycle life and energy density of lithium-ion batteries. However, characterization electrode architectures is complicated by heterogeneous mixture components nanoscale diameter particles, which falls beneath lateral depth resolution most laboratory-based instruments. In this work, we report an original scanning probe microscopy approach investigate microstructures with nanometer-scale via contrast in electronic...
We report the investigation of silicon nanoparticle composite anodes for Li-ion batteries, using a combination two nm-scale atomic force microscopy-based techniques: scanning spreading resistance microscopy electrical conduction mapping and contact resonance volume elastic modulus mapping, along with electron energy dispersion spectroscopy, nanoindentation, electrochemical analysis. Thermally curing anode—made polyethylene oxide-treated Si nanoparticles, carbon black, polyimide...
A study on polyimide binder for Li ion batteries, showing active lithiation/delithiation with first cycle capacity loss, formation of dendrite-like morphology, elastic modulus increase, and overall electronic resistivity increase during lithiation.
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Polyimide binders are often used in electrodes made with silicon for lithium-ion batteries their mechanical strength and adhesion, which help mitigate issues large volumetric expansion. These can be electrochemically active, but it is difficult to characterize what physical chemical changes occur due a composite electrode multiple components processes at play. In this work, we study consisting only of polyimide binder conductive carbon, using scanning probe-based techniques— contact...
Silicon oxides (SiO x ) have been considered as promising alternatives to pure Si in high energy anodes lithium-ion batteries (LIBs) due their improved cycling stability. However, fundamental lithiation mechanism has not yet systematically investigated, and potential collateral downsides remain unclear. In this work, we report on the role of oxygen lithiation/delithiation solid electrolyte interphase (SEI) formation processes SiO thin film model electrodes with different contents. We show...
Striking a balance between high theoretical capacity, Earth abundance, and compatibility with existing manufacturing infrastructure, silicon is one of the few materials that meets requirements for next-generation anode rechargeable lithium-ion batteries. Due to complications extreme volume changes during charging/discharging reactive interfacial chemistries, however, cycle-life silicon-based composite anodes unacceptable broad use. Developing majority formulation overcomes these challenges...
Silicon (Si) is a promising anode material for high energy density lithium-ion batteries (LIBs) but its poor cycling performance prevents large-scale adoption. Introducing Mg salt into the electrolyte has shown to form ternary Li-Mg-Si Zintl phase upon lithiation of Si and improve stability; however, formation mechanism impacts on solid interphase (SEI) are not yet well understood. Herein, we demonstrate via Magnesium (Mg) coated thin film electrode, where diffuses deposition in process. The...
Nanocomposite Si-graphite electrodes are a viable option for increasing the energy density and life of lithium-ion battery anodes. In comparison to model systems (e.g., Si wafer thin film), nanoparticles, ranging in diameter from tens hundreds nanometers, have higher rate capacity improved fracture toughness. 1, 2 However, characterization efforts better understand localized degradation mechanisms heterogeneous aging behaviors distinct components—Si, graphite, binder, conductive carbon—in...
Composite silicon-graphite (Si-Gr) anodes can improve battery energy density, due to Si’s high gravimetric capacity, while mitigating mechanical degradation of the anode and associated solid-electrolyte interphase (SEI) caused by Si expansion during lithiation. Optimizing these is challenging, partially difficulties characterizing 3D SEI structure its heterogeneity. We present multi-modal characterization on Si-Gr understand chemical composition how it relates properties. Results show...
Stabilizing solid electrolyte interphase (SEI) is a key factor for determining cell performance of Silicon (Si) anode, such as safety, cycle lifetime, calendar lifetime. Here, we found new potential stabilizing SEI the Si driven by crosstalk with cathode material. We investigated effect on chemistry anode function three different, representative materials: LiNi0.5Mn0.3Co0.2O2 (NMC532), LiNi0.8Mn0.1Co0.1O2 (NMC811), and LiFePO4 (LFP). Specifically, observed that significantly affected...
Silicon (Si) anodes have the potential to greatly improve energy density of lithium-ion batteries due greater specific capacity Si relative standard graphite (Gr) (1). However, anode implementation is limited by issues such as volumetric expansion during cycling and an unstable solid-electrolyte interphase (SEI). Composite with Gr particles can increase while mitigating degradation. these electrodes be challenging characterize (and therefore optimize) their multiple components, heterogeneous...
Due to inherent properties of the silicon (Si)-electrolyte interphase (SEI)—complexity, high reactivity and continuous evolution—it remains a poorly understood topic in advanced Si-based Li-ion battery (LiB) research, 1,2 its detailed real-time analysis is great challenge. Vibrational spectroscopy, such as Raman Fourier-transform infrared spectroscopy (FTIR), one most important analytical tools for understanding quantifying interfacial chemical reactions. These techniques are used...