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Liu, Haodong

Publications and source records attributed to Liu, Haodong.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Proton-exchange induced reactivity in layered oxides for lithium-ion batteries

LiNi x Co y Mn 1-x-y O 2 (0 < x, y < 1, NCM) is the dominant positive material for the state-of-the-art lithium-ion batteries. However, the sensitivity of NCM materials to moisture makes their manufacturing, storage, transportation, electrode processing and recycling complicated. Although it is recognized that protons play a critical role in their structure stability and performance, proton exchange with Li + in NCM materials has not been well understood. Here, we employ advanced characterizations and computational studies to elucidate how protons intercalate into the layered structure of NCM, leading to the leaching of Li + and the formation of protonated NCM. It is found that protonation facilitates cation rearrangement and formation of impurity phases in NCM, significantly deteriorating structural stability. The adverse effects induced by protons become increasingly pronounced with a higher Ni content in NCM. Through a comprehensive investigation into the thermodynamics and kinetics of protonation, we discover that Li deficiencies in NCM materials can be resolved via solution process in the presence of Li + ions and controlled proton concentration. The underlying mechanism of relithiation is further explored through materials characterizations and kinetics modeling. This work provides crucial insights into controlling structural and compositional defects of Li-ion battery positive material in complicated processing environment.

batteries↗
DOE OSTI2024

Healable and conductive sulfur iodide for solid-state Li–S batteries

Solid-state Li-S batteries (SSLSBs) are made of low-cost and abundant materials free of supply chain concerns. Owing to their high theoretical energy densities, they are highly desirable for electric vehicles. However, the development of SSLSBs has been historically plagued by the insulating nature of sulfur and the poor interfacial contacts induced by its large volume change during cycling, impeding charge transfer among different solid components. We report an S 9.3 I molecular crystal with I 2 inserted in the crystalline sulfur structure, which shows a semiconductor-level electrical conductivity (approximately 5.9 × 10 -7 S cm -1 ) at 25 °C; an 11-order-of-magnitude increase over sulfur itself. Iodine introduces new states into the band gap of sulfur and promotes the formation of reactive polysulfides during electrochemical cycling. Further, the material features a low melting point of around 65 °C, which enables repairing of damaged interfaces due to cycling by periodical remelting of the cathode material. As a result, an Li-S 9.3 I battery demonstrates 400 stable cycles with a specific capacity retention of 87%. The design of this conductive, low-melting-point sulfur iodide material represents a substantial advancement in the chemistry of sulfur materials, and opens the door to the practical realization of SSLSBs.

25 ENERGY STORAGE↗
DOE OSTI2023

HypoRiPPAtlas as an Atlas of hypothetical natural products for mass spectrometry database search

Abstract Recent analyses of public microbial genomes have found over a million biosynthetic gene clusters, the natural products of the majority of which remain unknown. Additionally, GNPS harbors billions of mass spectra of natural products without known structures and biosynthetic genes. We bridge the gap between large-scale genome mining and mass spectral datasets for natural product discovery by developing HypoRiPPAtlas, an Atlas of hypothetical natural product structures, which is ready-to-use for in silico database search of tandem mass spectra. HypoRiPPAtlas is constructed by mining genomes using seq2ripp, a machine-learning tool for the prediction of ribosomally synthesized and post-translationally modified peptides (RiPPs). In HypoRiPPAtlas, we identify RiPPs in microbes and plants. HypoRiPPAtlas could be extended to other natural product classes in the future by implementing corresponding biosynthetic logic. This study paves the way for large-scale explorations of biosynthetic pathways and chemical structures of microbial and plant RiPP classes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Structural and Interphasial Stabilities of Sulfurized Polyacrylonitrile (SPAN) Cathode

Sulfurized polyacrylonitrile (SPAN) has attracted a lot of attention because of its low cost, high capacity, and great reversibility. Due to its structural complexity and amorphous nature, reaction mechanism of SPAN is little understood. Here, for this paper, we study the structural and interphasial changes of SPAN using synchrotron-based pair distribution function (PDF) analysis and soft X-ray absorption spectroscopy (sXAS). PDF identifies key structural features, including C–S bond, sulfur dimer, and sulfur chain in SPAN. The sulfur dimer bridging the pyridine network partially converts to sulfur chain during the first charging. In the following cycles, sulfur chain goes through lithiation and delithiation with reversibility dependent on the electrolytes. SXAS reveals surface changes of SPAN. After the first cycle, a negatively charged carbon or fused benzene layer is formed, on top of which is another layer formed by the electrolyte decomposition. The layer formed by localized high concentration electrolyte is stable during cycling.

25 ENERGY STORAGE↗
DOE OSTI2022

Enhanced Electrolyte Transport and Kinetics Mitigate Graphite Exfoliation and Li Plating in Fast–Charging Li–Ion Batteries

Despite significant progress in energy retention, lithium-ion batteries (LIBs) face untenable reductions in cycle life under extreme fast-charging (XFC) conditions, which primarily originate from a variety of kinetic limitations between the graphite anode and the electrolyte. Through quantitative Li + loss accounting and comprehensive materials analyses, it is directly observed that the operation of LIB pouch cells at 4 C||C/3 (charging||discharging) results in Li plating, disadvantageous solid-electrolyte-interphase formation, and solvent co-intercalation leading to interstitial decomposition within graphite layers. It is found that these failure modes originate from the insufficient properties of conventional electrolytes, where employing a designed ester-based electrolyte improved the capacity retention of these cells from 55.9% to 88.2% after 500 cycles when operated at the aforementioned conditions. These metrics are the result of effective mitigation of the aforementioned failure modes due to superior Li + transport and desolvation characteristics demonstrated through both experimental and computational characterization. Finally, this work reveals the vital nature of electrolyte design to XFC performance.

25 ENERGY STORAGE↗
DOE OSTI2022

Overcoming the Intrinsic Limitations of Fast Charging Lithium‐Ion Batteries Using Integrated Acoustic Streaming

A lithium‐ion battery's maximum charge rate and energy density are intrinsically limited by the ion diffusion rate in the electrolyte. Most research focuses on materials science solutions to this problem, with gradual improvement over the years. A mechanical solution is proposed to integrate an MHz‐order frequency surface acoustic wave (SAW) device into an existing 1.8 Ah multilayered Li‐ion pouch cell to enhance the ion diffusion rate and the overall battery performance. Both the charging rate and cycling lifetime are improved from SAW. At a 6C (10 min) charge and C/3 discharge rate, typical of electric vehicle applications, integrating SAW into the Li‐ion cell doubles the energy density and maintains at least 72% of the battery's initial capacity after 2000 cycles. Moreover, using SAW quantifiably reduces battery degradation in these conditions as determined by optical imaging, scanning electron microscopy, X‐ray diffraction, and neutron diffraction. The use of SAW appears to offer a method to avoid undesirable Li metal plating on the graphite anode during charging, and leads to a much longer battery lifetime and good charge capacity, all despite rapid charging.

Huang, An↗
DOE OSTI2022

Pinned Electrode/Electrolyte Interphase and Its Formation Origin for Sulfurized Polyacrylonitrile Cathode in Stable Lithium Batteries

Sulfurized polyacrylonitrile (SPAN) represents one of the most promising directions for high-energy-density lithium (Li)-sulfur batteries. However, the practical application of Li||SPAN is currently limited by the insufficient chemical/electrochemical stability of electrode/electrolyte interphase (EEI). Here, a pinned EEI layer is designed for stabilizing a SPAN cathode by regulating the EEI formation mechanism in an advanced LiFSI/ether/fluorinated-ether electrolyte. Computational simulations and experimental investigations reveal that, benefiting from the nonsolvating nature, the fluorinated-ether can not only act as a protective shield to prevent the Li polysulfides dissolution but also, more importantly, endow a diffusion-controlled EEI formation process. It promotes the formation of a uniform, protective, and conductive EEI layer pinning into SPAN surface region, enabling the high loading Li||SPAN batteries with superior cycling stability, wide temperature performance, and high-rate capability. Finally, this design strategy opens an avenue for exploring advanced electrolytes for Li||SPAN batteries and guides the interface design for broad types of battery systems.

25 ENERGY STORAGE↗
DOE OSTI2022

A Nearly Zero-Strain Li-Rich Rock-Salt Oxide with Multielectron Redox Reactions as a Cathode for Li-Ion Batteries

Li-rich oxide cathodes are drawing increasing attention as next-generation cathode materials for the development of high-energy-density Li-ion batteries due to their strikingly high capacities. However, transition-metal migration, irreversible structural phase transformations, and the irreversible release of oxygen are responsible for rapid capacity and voltage decay. This study reports a Li-rich cation-ordered rock-salt oxide Li x V 0.4 Ti 0.4 O 2 (LVTO, x = 0.97/1.2) with space group Fd$\bar{3}$m that delivers a high capacity of over 250 mAh g -1 and capacity retention up to 89% after 50 cycles. A comprehensive experimental analysis confirms that the capacity can be attributed to the reversible V 3+ /V 5+ multielectron cationic redox reactions and a minor contribution from reversible anionic redox reactions. Importantly, LVTO exhibits nearly zero-strain behavior upon (dis)charge cycling cycles, which is associated with reversible V migration from octahedral to tetrahedral sites. Here our results demonstrate that Li-rich rock-salt oxide LVTO could be a promising cobalt-free cathode material for Li-ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2022

Hierarchically structured metal carbides as conductive fillers in thermo-responsive polymer nanocomposites for battery safety

Integrating thermo-responsive polymer switching materials (TRPS) into lithium-ion batteries (LIBs) has been recognized as one of the most effective strategies to prevent thermal runaway under various abuse scenarios. However, the current methods to obtain TRPS cannot satisfy different practical applications. Herein, we develop a versatile strategy for the preparation of various metal carbides (e.g., tungsten carbide, molybdenum carbide) with controllable hierarchical structure that is featured with surface protrusion structure, which is critical for high conductivity and rapid thermal response. Systematic studies of the phase and morphology evolutions by advanced characterizations illustrate that the reducing agent and reduction rate are critical for developing the specific morphology. In conclusion, by using the above-mentioned carbides as the conductive fillers of TRPS, the resulting TRPS with a specially controlled shape exhibits over 5 order of conductivity improvement compared with common carbides with particulate morphology, in addition to reversible shutdown performance and effective thermal abuse protections toward safe LIB operation.

25 ENERGY STORAGE↗
DOE OSTI2022

Chemical and structural evolutions of Li–Mn-rich layered electrodes at different current densities

Although the two active redox centers in Li-rich cathodes, including the anionic and cationic contributions, can enable Li-ion batteries to achieve outstanding specific energy, their behaviors at different current densities have not been clarified. In this report we provide a comparative study of transition metals (TMs) and oxygen redox activities by directly accessing their oxidation states in Li-rich materials operated at very different current rates. Our data reveal that the oxidation of oxygen in the near-surface region is at the same level for electrodes cycled with a wide range of current rates, indicating a reaction gradient of lattice oxygen redox reactions. The oxidation process of lattice oxygen is found to be dynamically compatible with that of the TMs. Combining the results of first principles calculations and complementary experimental findings, we propose a detailed mechanism of structural distortion from octahedral Li to tetrahedral Li and the role of oxygen vacancy in Li + diffusion. It is found that fast delithiation occurring at high current densities can easily cause local structural transformation, leading to a limited Li + diffusion rate and consequently suppressing rate capability.

25 ENERGY STORAGE↗
DOE OSTI2022

Solvent selection criteria for temperature-resilient lithium–sulfur batteries

All-climate temperature operation capability and increased energy density have been recognized as two crucial targets, but they are rarely achieved together in rechargeable lithium (Li) batteries. Herein, we demonstrate an electrolyte system by using monodentate dibutyl ether with both low melting and high boiling points as the sole solvent. Its weak solvation endows an aggregate solvation structure and low solubility toward polysulfide species in a relatively low electrolyte concentration (2 mol L −1 ). These features were found to be vital in avoiding dendrite growth and enabling Li metal Coulombic efficiencies of 99.0%, 98.2%, and 98.7% at 23 °C, −40 °C, and 50 °C, respectively. Pouch cells employing thin Li metal (50 μm) and high-loading sulfurized polyacrylonitrile (3.3 mAh cm −2 ) cathodes (negative-to-positive capacity ratio = 2) output 87.5% and 115.9% of their room temperature capacity at −40 °C and 50 °C, respectively. This work provides solvent-based design criteria for a wide temperature range Li-sulfur pouch cells.

25 ENERGY STORAGE↗
DOE OSTI2022

Isoxazole-Based Electrolytes for Lithium Metal Protection and Lithium-Sulfurized Polyacrylonitrile (SPAN) Battery Operating at Low Temperature

A new electrolyte system using isoxazole as the salt dissolving solvent has been developed and studied for lithium metal batteries. By using fluoroethylene carbonate (FEC) as an additive and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) as a diluent for localized high concentration electrolyte (LHCE), isoxazole-based electrolytes were successfully implemented in lithium metal batteries, demonstrating excellent lithium metal protection capability. Utilizing several advanced characterization techniques (including synchrotron-based X-ray absorption spectroscopy and photoelectron spectroscopy), the solid electrolyte interphase (SEI) formed on the Li-metal anode after employing these electrolytes was thoroughly investigated. The high ionic conductivity of isoxazole at low temperature and the low impedance of SEI formed in LHCE significantly improved the low-temperature performance of Li-sulfurized polyacrylonitrile (SPAN) batteries, delivering 273.8 mAh g −1 capacity at −30 °C with 99.85% capacity retention after 50 cycles.

25 ENERGY STORAGE↗
DOE OSTI2022

A Fiber-Based 3D Lithium Host for Lean Electrolyte Lithium Metal Batteries

3D hosts are promising to extend the cycle life of lithium metal anodes but have rarely been implemented with lean electrolytes thus impacting the practical cell energy density. To overcome this challenge, a 3D host that is lightweight and easy to fabricate with optimum pore size that enables full utilization of its pore volume, essential for lean electrolyte operations, is reported. The host is fabricated by casting a VGCF (vapor-grown carbon fiber)-based slurry loaded with a sparingly soluble rubidium nitrate salt as an additive. The network of fibers generates uniform pores of ≈3 µm in diameter with a porosity of 80%, while the nitrate additive enhances lithiophilicity. This 3D host delivers an average coulombic efficiency of 99.36% at 1 mA cm -2 and 1 mAh cm -2 for over 860 cycles in half-cell tests. Full cells containing an anode with 1.35-fold excess lithium paired with LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) cathodes exhibit capacity retention of 80% over 176 cycles at C/2 under a lean electrolyte condition of 3 g Ah -1 . This work provides a facile and scalable method to advance 3D lithium hosts closer to practical lithium-metal batteries.

36 MATERIALS SCIENCE↗