A5040523250- Advanced Battery Materials and Technologies
- Block Copolymer Self-Assembly
- Advancements in Battery Materials
- Advanced Battery Technologies Research
- Advanced Polymer Synthesis and Characterization
- Conducting polymers and applications
- Polymer Nanocomposites and Properties
- Polymer crystallization and properties
- Fuel Cells and Related Materials
- 3D Printing in Biomedical Research
- Polymer Surface Interaction Studies
- Electrostatics and Colloid Interactions
- Machine Learning in Materials Science
- Nanofabrication and Lithography Techniques
- Membrane Separation and Gas Transport
- Molecular Junctions and Nanostructures
- Nerve injury and regeneration
- Thermal properties of materials
- Theoretical and Computational Physics
- Bone Tissue Engineering Materials
- Liquid Crystal Research Advancements
- X-ray Diffraction in Crystallography
- Analytical Chemistry and Sensors
- Advanced X-ray Imaging Techniques
- Organic Electronics and Photovoltaics
University of Chicago
2022-2025
University of California, Berkeley
2017-2024
University of Wisconsin–Madison
2023-2024
Lawrence Berkeley National Laboratory
2021-2024
Berkeley College
2018
Massachusetts Institute of Technology
2015
We present experimental results on the phase behavior of block copolymer/salt mixtures over a wide range copolymer compositions, molecular weights, and salt concentrations. The system comprises polystyrene-block-poly(ethylene oxide) lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt. It is well established that LiTFSI interacts favorably with poly(ethylene relative to polystyrene. relationship between chain length composition at fixed temperature U-shaped, as seen in experiments...
The uncontrollable nonplanar electrodeposition of lithium is a significant barrier to the widespread adoption high energy density rechargeable batteries with metal anode. A promising approach for preventing growth dendrites use solid polymer electrolytes shear modulus. Current key variable in lithium. present study first attempt at quantifying effect current on geometry and other protrusions during through electrolyte. defects formed electrode were determined by X-ray microtomography....
Despite efforts to develop increasingly targeted and personalized cancer therapeutics, dosing of drugs in chemotherapy is limited by systemic toxic side effects. We have designed, built, deployed porous absorbers for capturing from the bloodstream after these had their effect on a tumor, but before they are released into body where can cause hazardous The support structure was built using 3D printing technology. This coated with nanostructured block copolymer outer blocks that anchor polymer...
The design and engineering of composite materials is one strategy to satisfy the needs systems with multiple orthogonal property requirements. In case rechargeable batteries lithium metal anodes, system requires a separator fast ion transport good mechanical strength. this work, we focus on polystyrene-block-poly(ethylene oxide) (SEO) bis(trifluoromethane)sulfonimide salt (LiTFSI). Ion occurs in salt-containing poly(ethylene oxide)-rich domains. Mechanical rigidity arises due glassy nature...
We investigate the effect of direct ionic current (dc) on morphology a block copolymer electrolyte in lithium symmetric cell. present situ X-ray scattering and transmission measurements as functions space time. In quiescent state, exhibits cylindrical (HEX) morphology. The depletion salt near negative electrode produces gyroid (GYR) phase three stages. early stage, domain spacing HEX decreases with time, expected due to depletion. intermediate new higher concentration nucleates, while...
The limiting current is an important transport property of electrolyte as it provides upper bound on how fast a cell can be charged or discharged. We have measured the in lithium-lithium symmetric cells with standard polymer electrolyte, mixture poly(ethylene oxide) and lithium bis(trifluoromethane) sulfonamide salt at 90°C. were polarized increasing density. steady-state potential was smooth function density until exceeded. An abrupt increase taken experimental signature current. fully...
We have measured the effect of added salt on chain dimensions mixtures poly(ethylene oxide) (PEO) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in melt state through small-angle neutron scattering (SANS) experiments. Scattering profiles from blends hydrogenated deuterated PEO mixed with LiTFSI were as a function concentration. pure PEO/LiTFSI used for background-subtraction purposes. The densities varying concentrations to calculate partial molar monomer volumes account nonideal...
The ability to control and manipulate semiconductor/bio interfaces is essential enable biological nanofabrication pathways bioelectronic devices. Traditional surface functionalization methods, such as self-assembled monolayers (SAMs), provide limited customization for these interfaces. Polymer brushes offer a wider range of chemistries, but choices that maintain compatibility with both lithographic patterning systems are scarce. Here, we developed class bioinspired, sequence-defined...
Understanding the distribution of ionic species in electrolytes is important for predicting ion-transport properties. Here, a quantitative analysis wide-angle X-ray scattering (WAXS) profiles was conducted first time on series mixtures poly(ethylene oxide) (PEO) and lithium bis(trifluoromethanesulfonyl)imide salt (LiTFSI), PEO/LiTFSI, as function concentration melt state. Abnormal signatures were observed: while WAXS data showed single peak (Peak 1) absence salt, second 0) appeared at lower...
Hierarchical structure-within-structure assemblies offer a route toward increasingly complex and multifunctional materials while pushing the limits of block copolymer self-assembly. We present detailed study self-assembly series fluorinated high-χ copolymers (BCPs) prepared via postmodification single poly(styrene)-block-poly(glycidyl methacrylate) (S-b-G) parent polymer with alkylthiol pendent groups containing 1, 6, or 8 carbons (termed trifluoro-ethanethiol (TFET), perfluoro-octylthiol...
Nanostructured solid electrolytes containing ion-conducting domains and rigid nonconducting are obtained by block copolymer self-assembly. Here, we report on the synthesis characteristics of mixtures a hybrid diblock with an organic inorganic block: poly(ethylene oxide)-b-poly(acryloisobutyl polyhedral oligomeric silsesquioxane) (PEO–POSS) lithium salt. In neat state, PEO–POSS exhibits classical order-to-disorder transition upon heating. Dilute exhibit dramatic reversal; disorder-to-order...
Successful prevention of lithium dendrite growth would enable the use metal as an anode material in next-generation rechargeable batteries. Mechanically stiff block copolymer electrolytes have been shown to prolong life cells by partially suppressing growth. However, impurity particles that are invariably present nucleate electrodeposition defects eventually lead short circuits. In this study, we X-ray tomography study morphology electrodeposited symmetric containing a electrolyte. An...
It is known that the addition of salts to symmetric block copolymers leads stabilization ordered phases and an increase in domain spacing; both trends are consistent with effective Flory-Huggins interaction parameter between blocks, χ. In this work, we show salt a disordered asymmetric copolymer first formation coexisting which give way reentrant phase at higher concentration. The body centered cubic (BCC) different spacings, stabilized by partitioning salt. Further concentration results yet...
We demonstrate that lithium metal is sparingly soluble in poly(ethylene oxide) (PEO). 7Li NMR shows when a PEO sample placed contact with at elevated temperatures, species dissolves and diffuses into the bulk polymer. A lithium/PEO/lithium electrochemical cell, containing no salts, increasing conductivity over time annealed 120 °C. Chronoamperometry cell obeys Ohm’s law, implying conduction occurs without development of concentration gradients. To explain results, it proposed atomic PEO,...
ABSTRACT The objective of this review is to organize literature data on the thermodynamic properties salt‐containing polystyrene/poly(ethylene oxide) (PS/PEO) blends and polystyrene‐ b ‐poly(ethylene (SEO) diblock copolymers. These systems are interest due their potential serve as electrolytes in all‐solid rechargeable lithium batteries. Mean‐field theories, developed for pure polymer block copolymers, used describe phenomenon seen systems. An effective Flory–Huggins interaction parameter, χ...
We investigate the segmental dynamics and ion transport in two chemically distinct polymer electrolytes, poly(2-cyanoethyl acrylate) (PCEA) poly(ethylene oxide) (PEO), their mixtures with lithium bis(trifluoromethane)sulfonimide (LiTFSI) salt. Quasi-elastic neutron scattering experiments reveal slow PCEA/LiTFSI relative to that PEO/LiTFSI, translating monomeric friction coefficients are orders of magnitude different. In spite enhanced salt dissociation PCEA due presence polar groups, is...
This study shows that it is possible to obtain homogeneous mixtures of two chemically distinct polymers with a lithium salt for electrolytic applications. approach motivated by the success using organic solvents in modern lithium-ion batteries. The properties polyether, poly(ethylene oxide) (PEO), poly(ether-acetal), poly(1,3,6-trioxocane) (P(2EO-MO)), and bis(trifluoromethanesulfonyl)imide (LiTFSI) were studied small-angle neutron scattering (SANS) electrochemical characterization symmetric...
A fundamental understanding of mixtures poly(ethylene oxide) (PEO) electrolytes and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is important for developing solid rechargeable batteries. Here, we quantify the salt activity coefficient polymer chain statistics PEO/LiTFSI mixture at experimentally relevant concentrations using molecular dynamics simulations. Near critical concentration, rc = 1/6 [Li+]/[EO], our simulation shows emergence a small plateau in dependence on concentration....
Next-generation electrolytes for lithium batteries must be able to conduct ions at sufficiently high current densities; yet this regime is rarely studied directly. The limiting density of an electrolyte quantifies the highest possible rate ion transport under applied dc potential. Herein, we report on in twelve nanostructured polystyrene-block-poly(ethylene oxide) (PS-b-PEO, or SEO) copolymer electrolytes. We find that a given salt concentration increases systematically with increasing...
The reduction of sulfur during discharge in a lithium-sulfur (Li-S) cell is known to occur series reaction steps that involve lithium polysulfide intermediates. We present an operando study the solid-state Li-S using X-ray absorption spectroscopy (XAS). In theory, average chain length polysulfides, xavg,cell, at given depth determined by number electrons delivered cathode. dependence xavg,cell measured XAS on excellent agreement with theoretical predictions. also used track formation Li2S,...
The effects of salt-doping on the morphological behavior block copolymers are well established but remain poorly understood, partially because challenge resolving electrostatics in a heterogeneous medium with low average permittivity. By employing recently developed field theory, we analyze phase polystyrene-b-poly(ethylene oxide) (SEO) doped lithium bis(trifluoromethanesulfonyl)imide salts (LiTFSI). Using single fitting parameter, ionic solvation radius, obtain qualitative agreement between...
The self-assembly of block copolymers (BCPs) is dictated by their segregation strength, χN, and while there are well-developed methods for determining χ in the weak strong regimes, it challenging to accurately measure with intermediate strengths, especially when have inaccessible order-disorder transition temperatures. χeff often approximated using theory (SST), but utilizing these values estimate interface width (wm) BCPs regime results predictions that deviate significantly from measured...