A review of Hu Liangbing‘s classic achievements

Biography

Liangliang Hu received a bachelor‘s degree in physics from the University of Science and Technology of China in 2002 and worked with Professor Zhang Yuheng to study giant magnetoresistive (CMR) materials for three years. During his PhD, he focused on carbon nanotube-based nanoelectronics (2002-2007) at the University of California, Los Angeles (in collaboration with George Gruner). In 2006, he joined Unidym Inc (www.unidym.com) as a co-founding scientist. At Unidym, Liangbing‘s role is to develop roll-to-roll printed carbon nanotube transparent electrodes and integrate the device into touch screens, LCDs, flexible OLEDs and solar cells. He worked at Stanford University (in collaboration with Yi Cui) from 2009 to 2011, where he studied various energy devices based on nanomaterials and nanostructures. He is currently an associate professor at the University of Maryland, College Park. His research interests include nanomaterials and nanostructures, roll-to-roll nanofabrication, focusing on energy storage in solid-state and Na-ion batteries, and printed electronics. He has published more than 200 research papers (total citations:> 15,000), and invited more than 70 international conference reports . He has received many awards, including: Nano Letters Young Investigator Lectureship (2017), Naval Research Office Young Researcher Award (2016), ACS Energy and Fuel Emerging Researcher Award (2016), SME Outstanding Young Manufacturing Engineer Award (2016), University of Maryland Junior Teacher Award (School of Engineering, 2015), 3M Non-Lifetime Faculty Award (2015), Maryland Outstanding Young Engineer (2014), University of Maryland Annual Invention Award (2014 Physical Science), American Academy of Engineering Education Campus Star (2014), Air Force Young Researcher Award (AFOSR YIP, 2013). Dr. Hu is the (founding) director of the Advanced Paper and Textile Center (CAPT) at the University of Maryland, College Park. He is also the co-founder of Inventwood Inc., working to further commercialize the cellulose nanotechnology mentioned above. He is mainly engaged in the research of wood fiber-based nanofibers and nanocrystallites; he focuses on the application of nanocellulose in optical and electrical applications and high performance and low cost new energy devices.

Thesis results:

Materials Today: High-performance assembly of graphene materials between on and off

Associate Professor Hu Liangbing (corresponding author), Dr. Yanan Chen (first author), Dr. Yilin Wang (co-author) and associate researcher Lin Yi (corresponding author) from the National Aeronautics and Astronautics Institute jointly published a research article on Materials Today from the University of Maryland , Entitled "Nanomanufacturing of Graphene Nanosheets through Nano-Hole Opening and Closing." The authors report the assembly of high-density, high-quality graphene phase materials by controlling the opening and closing of nanopores on graphene nanosheets. The nanopores induced on the graphene nanosheets are used to achieve dry pressing or molding of porous graphene, and also to quickly remove solvents during liquid phase processing. After molding, the nanopores on the nanosheets can be quickly and quickly closed or repaired at high temperatures by electrical heating (~ 2700K). Unlike traditional high temperature processing in graphite furnaces, Joule‘s electric heating speed is fast, up to several milliseconds [Reference], low cost, and can cause ultra-high resistance at the junctions between graphene nanosheets with higher resistance high temperature. Self-repairing thermal reduction makes it possible to form crosslinks between adjacent graphene nanoplatelets at the defect, which helps to build a high-density graphene structure, resulting in high electrical and thermal conductivity. Molecular dynamics (MD) simulations indicate that closed pores or repair mechanisms involve the reconstruction of conjugated carbon structures, in which carbon radicals fill and repair nanopores at high temperatures. The closed graphene phase structure showed excellent electrical conductivity (2209 S / cm), thermal conductivity (863W / mK), and mechanical strength.

Literature link: Nanomanufacturing of Graphene Nanosheets through Nano-Hole Opening and Closing , (https://doi.org/10.1016/j.mattod.2018.09.001)

EES: Flexible Li-CO2 battery with ultra-high capacity and stable cycling

At the University of Maryland Huliang Bing Jiaoshou (corresponding author) under the leadership of the team, and the NASA Langley Research Center and the National Institute of Aeronautics and Astronautics cooperation, based on the report of the high-capacity flexible cathode, mechanically flexible and highly charged Li-CO ₂ battery, which uses the natural structure of wood. The microchannels (containers and cavities) in the wooden structure ensure sufficient CO ₂ gas flow, while the nanochannels in the cell walls (the gaps between the cellulose nanofibers) are filled with electrolyte. In addition, cellulose nanofibers in wood can absorb electrolytes and form nano-ion channels, improving ion transport in the cathode. In addition, by placing a ruthenium (Ru) modified carbon nanotube (CNT) network on the inner wall of the microchannel, a sufficient surface area is provided for the deposition of discharge products. During the discharge, the CO ₂ gas flowing through the micro-channel encounters lithium ions from the nano-ion channel and electrons from the CNT network on the channel wall to form the discharge product Li ₂ CO ₃ . During recharging, Li ₂ CO ₃ solids are decomposed into lithium ions and CO ₂ gas, which can be quickly transferred away along the channel walls and microchannels, respectively. Therefore, there are no transportation obstacles in this Li-CO ₂ battery design, which ensures the excellent rechargeability of the system. The proposed Li-CO ₂ battery based on a flexible wood-based cathode can stably cycle 200 times while maintaining 1000 mA hg _c ^-1High capacity and low overpotential of 1.5 V. In addition, because the wood structure facilitates the transport of CO ₂ gas and lithium ions, high capacity can be maintained even with ultra-thin cathodes. A high capacity of 11 mAh cm ^-2 has been achieved using a 2 mm thick cathode . In addition to its significant electrochemical performance, and the partial removal of lignin and hemicellulose through chemical treatment, wood-based cathodes have excellent mechanical flexibility, bringing hope for potential applications in flexible and wearable devices. Related results were published on the EES under the title of " Flexible lithium-CO ₂ battery with ultrahigh capacity and stable cycling " .

Literature link : Flexible lithium-CO ₂ battery with ultrahigh capacity and stable cycling (EES, 2018, DOI: 10.1039 / C8EE01468J)

Adv. Mater .: Muscle-inspired highly anisotropic, high-strength, and ion-conducting hydrogel

Professor Hu Liangbing‘s group at the University of Maryland combines the characteristics of high tensile strength of natural wood with the flexibility and high water content of hydrogels to achieve the preparation of highly anisotropic, high-strength, and ion-conducting wood hydrogels. Studies have shown that there is a strong hydrogen bonding and cross-linked structure between ordered cellulose nanofibers and polymer molecular chains, which makes the tensile strength of wood hydrogels as high as 36 MPa, which is the highest reported hydrocoagulation. One of the glue materials. In addition, due to the negative charge of the ordered cellulose nanofibers, the wood hydrogel can also be used as a nanofluid conduit to achieve ion selective transmission functions similar to biological muscle tissue. The work was published on Advanced Materials under the title " Muscle-Inspired Highly Anisotropic, Strong, Ion-Conductive Hydrogels" .

Literature link: Muscle-Inspired Highly Anisotropic, Strong, Ion-Conductive Hydrogels (Adv. Mater. 2018, DOI: 10.1002 / adma.201801934)

Adv. Energy. Mater .: In situ assembly of "chain catalyst" in a low-curvature hierarchical carbon framework and its efficient and stable hydrogen evolution reaction

In Hu Liangbing University of Maryland professor (author) , and led by the University of Pittsburgh cooperation, in operation, heat shock processing method by Joule heating Ultrafast embedded nitrogen (N) in a porous carbonized wood (CW) based carbon substrate Doped graphene-coated nickel-iron (NiFe) core-shell nanoparticles (NC-NiFe). Due to the ultra-high heating and quenching rates, metal salt precursors rapidly decompose on carbon supports and redistribute into nucleation into ultrafine metal alloy nanoparticles. Thermal shock-induced NC-NiFe nanoparticles have a smaller average size (22.5 nm) and a thinner graphene shell (1 to 4 layers). NC-NiFe electrocatalysts are evenly anchored on CNTs and grow in situ within wood-derived carbon microchannels (CW-CNT @ NC-NiFe), which facilitates rapid electron transport. The open CW-CNT frame has low-bending microchannels that can promote hydrogen release and electrolyte penetration. The results show that the self-supporting CW-CNT @ NC-NiFe electrodes exhibit impressive electrochemical performance in terms of hydrogen precipitated, small Tafel slopes, as mV On Dec 52.8 ^-1 and mA cm & lt In 10 ^-2 through at The potential is 179 mV and has good long-term cycling stability. Even after 10,000 cycles, the polarization curve of this CW-CNT @ NC-NiFe electrode has remained basically unchanged. This newly developed simple but effective thermal shock treatment method is a potential alternative to the rapid in situ self-assembly of nanoparticles in a conductive support, which can be extended to other highly efficient electrocatalytic applications. Related results are titled " In Situ" Chainmail Catalyst "Assembly in Low - Tortuosity, Hierarchical Carbon Frameworks for Efficient and Stable Hydrogen Generation"Published in Adv. E nergy . Mater. On.

Literature link : In Situ “Chainmail Catalyst” Assembly in Low-Tortuosity, Hierarchical Carbon Frameworks for Efficient and Stable Hydrogen Generation (Adv. Energy. Mater., 2018, DOI: 10.1002 / aenm.201801289)

ACS Nano: Application of Epitaxially Connected Carbon Nanotube Films in Water Battery Current Collectors

Liangliang Hu (corresponding author) of the University of Maryland (corresponding author) and others proposed a "epitaxial welding" strategy, designed to form carbon nanotube (CNT) aggregates as highly crystalline and interconnected structures. Polyacrylonitrile solution was coated on CNTs as "nano glue" to physically connect CNTs to form a network structure, and then subjected to rapid high temperature annealing (> 2800 K, about 30 minutes) to graphitize the polymer coating into a crystalline layer and make the phase Adjacent CNTs form interconnected structures. Contact-welded CNTs (W-CNTs) exhibit high electrical conductivity (~ 1500 S / cm) and high tensile strength (~ 120 MPa), which are 5 and 20 times higher than unwelded CNTs, respectively. In addition, W-CNTs show good chemical and electrochemical stability in the strong acid / alkaline electrolyte (> 6mol / L) when performing a potentiostatic test at the cathode and anode potentials. With these outstanding properties, W-CNT films will be the best choice for high-performance current collectors, and this result has been proven in aqueous batteries with "water in salt" electrolytes. Related results were published on ACS Nano under the title " Epitaxial Welding of Carbon Nanotube Networks for Aqueous Battery Current Collectors " .

Reference link: Epitaxial Welding of Carbon Nanotube Networks for Aqueous Battery Current Collectors (ACS Nano, 2018, DOI: 10.1021 / acsnano.7b08584).

Advanced Energy Materials: 3D wettability framework for dendritic alkali metal anodes

The paper “ 3D Wettable Framework for Dendrite ‐ Free Alkali Metal Anodes ” by Professor Hu Liangbing ‘s research group (corresponding author) at the University of Maryland was published in the Energy Journal Advanced Energy Materials (Impact Factor: 16.72 ) . Zhang Ying (one piece), Wang Chengwei (one piece), and Glenn Pastel (one piece) Researchers have reported a three-dimensional frame made of carbon fiber (CF) as a stable framework to pre-store lithium metal or sodium metal (Li / Na-CF composite) (Figure 1b). CF is a unique coaxial structure composed of a conductive carbon core, an alloy transition layer with high alkali metal wettability, and an externally attached Li or Na metal layer. As shown in Figure 1c, the 3D frame with high specific surface area guarantees sufficient electrolyte / electrode contact, and can achieve rapid charge transfer during Li / Li + or Na / Na + redox reactions. By reducing the local current density, the dendrite growth is effectively suppressed and the porous structure limits the volume change during charge and discharge. Compared with previously reported 3D current collectors (such as 3D Cu and Ni foam), the Li / Na-Sn transition layer has the following four advantages: 1) The formation of Li / Na-Sn composites greatly reduces the hot molten alkali Surface energy between metal and SnO2, which drives the introduction of alkali metals into the lightweight porous CF matrix; 2) The formed Li / Na-Sn alloy regulates the interface mass transfer between the 3D carbon framework and the alkali metal; 3 ) The Li / Na-Sn alloy layer provides a large number of electrochemically active sites to guide uniform Li / Na nucleation and avoid severe dendrite growth; 4) The Li / Na-Sn alloy transition layer has an ion conductive property than the bulk Alkali metals have higher diffusion coefficients; for example, the lithium metal itself has an ionic diffusion coefficient of 5.7 × 10 ^-11 cm ² s ^-1 , compared with Li-Sn alloys which show a higher ionic diffusion coefficient of 6.6 × 10 ^-8 to 5.6 × 10 ^-7 cm ² s ^-1 (room temperature). Therefore, compared to bare carbon, an alkali metal electrode with a Li / Na-Sn intermediate transition layer provides rapid kinetics for uniform nucleation. These improvements also improve cycle performance and safety compared to alkali metal pole pieces and 3D current collectors.

Literature link: 3D Wettable Framework for Dendrite-Free Alkali Metal Anodes , Advanced Energy Materials, 2018, DOI: 10.1002 / aenm.201800635

Science cover: Synthesis of eight-element high-entropy alloys

On March 30, 2018, Beijing time, Science published online the University of Maryland, Hu Liangbing, University of Illinois at Chicago Reza Shahbazian-Yassar, Johns Hopkins University Chao Wang, MIT Ju Li (Communications) and others entitled " Carbothermal shock synthesis of high-entropy-alloy nanoparticles ". The study was carried out by thermal shock on a mixture of precursor metal salts supported on a carbon support [temperature ~ 2000 K, duration of 55 ms, rate of ~ 10 ⁵ K per second]. It is proposed to alloy eight different elements into single-phase solid solution nanoparticles (commonly referred to as high-entropy alloy nanoparticles (HEA-NP). By controlling carbon thermal excitation (CTS) parameters (substrate, temperature, impact duration, and heating) / Cooling rate) to synthesize a wide range of multicomponent nanoparticles with the desired chemistry (composition), size, and phase (solid solution, phase separation). To demonstrate practicality, the experimenters synthesized five-element HEA-NPs as ammonia oxidation Catalyst with ~ 100% conversion and> 99% nitrogen oxide selectivity. The first author of this article was Yao Yonggang, and Sara E. Skrabalak of Indiana University of Bloomington made the title "Mashing up metals with carbothermal shock" "Perspective, Science is also highlighted as this week in science.

Literature link: Carbothermal shock synthesis of high-entropy-alloy nanoparticles (Science, 2018, DOI: 10.1126 / science.aan5412 )

Science Advance: Anisotropic nanocellulose used as a super-insulating nanomaterial

Professor Liangbing Hu of the University of Maryland and Professor Ronggui Yang (co-corresponding author) of the University of Colorado have demonstrated the excellent thermal management capabilities of cellulose nanofibers made directly from wood, hereinafter referred to as nanomaterials. This material exhibits anisotropic thermal properties. The thermal conductivity is very low in the transverse direction (vertical to the nanofibrils), which is 0.03W / m · K. The thermal conductivity in the axial direction is about two Times, 0.06W / m · K. The anisotropy of thermal conductivity enables nanomaterials to efficiently dissipate heat in the axial direction while generating thermal insulation in the lateral direction. In addition, nanomaterials exhibit an emissivity of less than 5% on the solar spectrum and can effectively reflect solar thermal energy. The achievement, titled "Anisotropic, lightweight, strong, and super thermally insulating nanowood with naturally aligned nanocellulose" , was published in the journal Science Advance this morning . The first author of the paper is Dr. Li Tian.

Literature link: Anisotropic, lightweight, strong, and super thermally insulating nanowood with naturally aligned nanocellulose (Science Advance, 2018, DOI: 10.1126 / sciadv.aar3724)

Chem: Elastic Wood Carbon Sponge

Professor Liangliang Hu and Professor Teng Li from the University of Maryland, Professor Xie Jia (co-corresponding author) from Huazhong University of Science and Technology, etc., make highly lightweight and compressible charcoal directly from natural balsa wood through a scalable and sustainable top-down approach sponge. Chemical treatment removes lignin and hemicellulose from the wood cell wall, and directly transforms the lattice-like rigid wood structure into a spring-like compressible layered structure. Charcoal sponges exhibit superior mechanical properties and sensitive electrical responsiveness as strain sensors. The achievement was published in the journal Chem under the title " Scalable and Sustainable Approach toward Highly Compressible, Anisotropic, Lamellar Carbon Sponge " .

Literature link: Scalable and Sustainable Approach toward Highly Compressible, Anisotropic, Lamellar Carbon Sponge (Chem, 2018, DOI: https://doi.org/10.1016/j.chempr.2017.12.028)

Nat. Energy: Thermoelectric Properties of Flexible Reduced Graphene Oxide Film at 3000 K

Professor Liangbing Hu of the University of Maryland and Dennis H. Drew (co-corresponding author) and others showed a thermoelectric conversion material based on high-temperature reduction graphene oxide nanosheets. After the researchers carried out the reduction treatment at 3300 K, the conductivity of the nanosheet film at 3000K increased to 4000 Scm ^-1 and the power factor S2σ was as high as 54.5 μWcm ^-1 K ^-2 . Reported measurements characterize the film‘s thermoelectric performance up to 3000 K. The reduced graphene oxide film also exhibits high broadband radiation absorption and can act as a radiation receiver and thermoelectric generator. The achievement was published in the journal Nature Energy on February 5, 2018 under the title " Thermoelectric properties and performance of flexible reduced graphene oxide films up to 3,000 K " . The first author of the paper is Dr. Li Tian.

Literature link : Thermoelectric properties and performance of flexible reduced graphene oxide films up to 3,000 K (Nat. Energy, 2018, doi: 10.1038 / s41560-018-0086-3)

Adv. Funct. Mater .: Efficient Mesoporous Wood Solar Steam Generator

Professor Liangbing Hu (corresponding author) of the University of Maryland, USA and others published the research results "Scalable and Highly Efficient Mesoporous Wood-Based Solar Steam Generation Device: Localized Heat, Rapid Water Transport" in the journal Advanced Functional Materials on February 21, 2018 . . The solar steam generator is designed to transport water across the plane in the wood through nano-scale channels, and the heat transfer direction is decoupled to reduce conductive heat loss. A high steam power generation efficiency of 80% is achieved in one sun, and a high steam power generation efficiency of 89% is achieved in 10 suns. Cross plates perpendicular to the mesoporous wood can provide rapid water delivery through recesses and spirals. Cellulose nanofibers are distributed circularly around the recesses and aligned along the spiral height to pass water through the lumen. At the same time, the anisotropic heat conduction of mesoporous wood can provide better insulation performance than ultra-insulated polystyrene foam (≈0.03W m ^-1 K ^-1 ). Wood exhibits a thermal conductivity of 0.11 W m ^-1 K ^-1 in the transverse direction . The solar steam generator has the prospect of cost-effectiveness and large-scale application under solar irradiance.

Literature link : Scalable and Highly Efficient Mesoporous Wood-Based Solar Steam Generation Device: Localized Heat, Rapid Water Transport (Adv. Funct. Mater., 2018, DOI: 10.1002 / adfm.201707134)

Adv. Mater .: 3D printing of extruded multilayer porous advanced battery electrodes

At the University of Maryland Hu Liangbing Jiaoshou (corresponding author) Task Force under the leadership of the US National Space Institute and NASA‘s Langley Research Center in cooperation, through simple one-step oxidation process, graphene powder can be synthesized highly porous nanomaterials (Called hG). During hG synthesis, nano-sized vias are formed by removing defective carbon from the original graphene sheet. In this study, hG was selected as the carbon precursor to produce a highly porous GO material (called hGO), which was made into an aqueous and additive-free ink for extrusion-based 3D printing. Independent 3D printed hGO grids exhibit three-peak porosity: nano-scale (4-25 nm through-holes on hGO sheets), micro-scale (tens of micron-sized holes introduced by lyophilization) and macro-scale (<500 μm square hole network) Pore design), which is beneficial for high-performance energy storage devices that rely on interfacial reactions to promote complete active site utilization. Under full discharge conditions, nanoporous r-hGO grid cathodes are superior to non-nanoporous GO-based grid cathodes in terms of cycle depth and stability. By not optimizing the Ru catalyst modification, the recyclability of the nanoporous r-hGO grids was doubled. Related results were published on Advanced Materials under the title "Extrusion-Based 3D Printing of Hierarchically Porous Advanced Battery Electrodes" .

Literature link: Extrusion-Based 3D Printing of Hierarchically Porous Advanced Battery Electrodes(Adv. Mater., 2018, DOI: 10.1002 / adma.201705651)

Nature: Leap from small wood to high-performance structural materials

On February 8, 2018, Beijing time, Nature published an article entitled " Processing bulk natural wood into a high-performance structural materia l" by University of Maryland Hu Liangbing and Teng Li (common communication) . The team developed a simple and An effective strategy to directly transform a block of natural wood into a high-performance structural material, which has a tenfold increase in strength, toughness and ballistic resistance, and has greater dimensional stability. Partial removal of lignin and hemicellulose from natural wood through a boiling process in an aqueous mixture of NaOH and Na ₂ SO ₃ followed by hot pressing results in complete collapse of the cell wall and natural wood with highly consistent cellulose nanofibers Fully densified. This strategy has proven to be universally effective for a variety of woods. The processed wood has a higher specific strength than most structural metals and alloys, making it a low-cost, high-performance, lightweight alternative.

Literature link: Processing bulk natural wood into a high-performance structural material (Nature, 2018, DOI: 10.1038 / nature25476)

Adv. Mater: 3D printed electrolytes for solid-state batteries

Professor Liliang Hu and Professor Eric D. Wachsman (co-corresponding author) at the University of Maryland have produced Li7La3Zr2O12 solid electrolyte through 3D printing technology. Using unique garnet inks, the researchers printed and sintered samples of possible structures, revealing thin and non-planar complex structures composed of only LLZ solid electrolyte. The area specific resistance of the 3D printed symmetrical Li | LLZ | Li battery is very low in the electrochemical cycle test. Using 3D printing technology to further study and optimize the structure of the electrolyte can make the solid area battery‘s area specific resistance significantly lower, and at the same time make The battery has a higher energy density and power density. In this work, more designs and structures are available. The reported ink formulation can be easily modified for use with other solid electrolytes or ceramic materials and can be extended to other related fields. The related research achievement " 3D-Printing Electrolytes for Solid-State Batteries " was published on Advanced Materials (first author Dr. Dennis W. McOwen, Dr. Xu Yi) .

Literature link: “ 3D-Printing Electrolytes for Solid-State Batteries ” ( Adv. Mater., 2018, DOI: 10.1002 / adma.201707132 )

Adv. Energy Mater .: Carbon nanotube-cellulose nanofiber composite current collector for acidic water battery

The team of Professor Liangbing Hu (corresponding author) of the University of Maryland, College Park, USA , started from the decolorized cork pulp solution and obtained it through 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) -assisted oxidation The coarser cellulose fibers are pressed to obtain finer cellulose nanofibers (CNF), which are then compounded with carbon nanotubes (CNTs). The CNT-CNF composite film is obtained by vacuum filtration. The CNT-CNF film is composed of carbon fiber. The thickness can be controlled within 10 μm, the density is only 1.12 g / cm ³ , the direct current conductivity can reach 704 S / cm, and the elastic modulus is higher than 60 MPa. In the CNT-CNF composite structure, CNTs are mainly used to provide conductive paths, while CNF mainly provides mechanical strength and can improve the dispersibility of CNTs on the surface of CNF. The CNT-CNF composite film is used as a current collector in a strongly acidic aqueous battery. It exhibits excellent electrical properties at a potential as high as 1.7 V (relative to Ag / AgCl) and as low as -0.5 V (relative to Ag / AgCl). Chemical stability. After immersing the CNT-CNF film in a 5 M sulfuric acid solution for 4 months, the morphology of the CNT-CNF film did not change significantly, and the conductivity was still as high as 575 S / cm. Compared with a commercially available activated carbon paper (ACC) current collector, the CNT-CNF composite current collector has higher electrochemical stability and can replace metal current collectors and ACC current collectors in aqueous battery systems. It is estimated that the total cost of the CNT-CNF composite film is only 1.027 $ / m ² , which is much lower than the cost of the metal current collector under the same conditions. The research results were published under the title of " Highly Conductive, Light Weight, Robust, Corrosion-Resistant, Scalable, All-Fiber Based Current Collectors for Aqueous Acidic Batteries ".Adv. Energy Mater .

Literature link: Highly Conductive, Light Weight, Robust, Corrosion-Resistant, Scalable, All-Fiber Based Current Collectors for Aqueous Acidic Batteries (Adv. Energy Mater., 2017, DOI: 10.1002 / aenm.201702615)

AEM: A General Welding Strategy for Lithium-Sodium Alloys on Different Battery Substrates

Associate Professor Hu Liangbing from the University of Maryland published a paper entitled " Universal Soldering of Lithium and Sodium Alloys on Various Substrates for Batteries " in the famous journal Advanced Energy Materials . The first author is Dr. Wang Chengwei, and the co-first author is a PhD candidate China. This article reports a general-purpose soldering technique that can quickly apply molten metallic lithium or metallic sodium on different substrates for solid-state batteries and other applications. By adding the alloy component, both the surface energy and the viscosity of the molten lithium are increased. Li-rich molten alloys exhibit good wettability on ceramic, metal, and polymer substrates. When the welding coating technology is applied to a solid state battery, the molten lithium tin alloy is successfully coated on the freshly polished garnet ceramic sheet within 10 seconds, as in a rapid welding process. The SEM image confirmed the close contact between the alloy and the garnet surface, and its interface impedance was only 7Ω cm ² . The lithium insertion-extraction cycle test confirmed the stability of the interface contact between the lithium-rich alloy anode and garnet SSEs. The same wetting behavior was also observed when sodium-based molten alloys and sodium-tin alloys were applied to alumina substrates.

Literature link : Universal Soldering of Lithium and Sodium Alloys on Various Substrates for Batteries (Adv. Energy. Mater .: 10.1002 / aenm.201701963)

Adv. Energy. Mater: "Breathing Wood" Makes High Performance Lithium Oxide Battery

The team of Professor Liangbing Hu (corresponding author) of the University of Maryland, College Park, USA published the latest research results " Hierarchically Porous, Ultrathick," Breathable "Wood-Derived Cathode for Lithium-Oxygen Batteries " on Advanced Energy Materials . , Currently works in the School of Chemistry and Chemical Engineering of South China University of Technology. In this article, the researchers took inspiration from wood with a hierarchical porous structure in nature, and designed a "breathable" carbonized and activated wood as the base, loaded ruthenium nanoparticles in its porous micropores, and constructed lithium. Oxygen battery cathode material. The micropores are beneficial for oxygen diffusion and transmission. The presence of rich multi-stage pores allows the positive electrode material to be completely wetted by the electrolyte. The thin electrolyte layer formed on the walls of the channels ensures rapid lithium ion transport. Lithium-oxygen batteries with carbonized active wood / ruthenium (thickness of about 700 μm) as the positive electrode exhibit high area specific capacitance (0.1 mA cm ^-2 current density, 8.58 mA h cm ^-2 ) and excellent charge-discharge cycle performance; if Increasing the thickness of the positive electrode to 3.4 mm will increase the area specific capacitance of the lithium-oxygen battery to 56.0 mA h cm ^-2 .

Literature links : Hierarchically Porous, Ultrathick, “Breathable” Wood-Derived Cathode for Lithium-Oxygen Batteries , (Adv. Energy. Mater, 2017, DOI: 10.1002 / aenm.201701203)

Adv. Mater .: Ultra-fine nano silver particles help deposit lithium metal to form a stable lithium metal anode

The article "Ultrafine Silver Nanoparticles for Seeded Lithium Deposition toward Stable Lithium Metal Anode" published by Associate Professor Hu Liangbing of the University of Maryland, College Park in Adv. Mater. Reported a new method to improve the performance and application of lithium metal batteries, namely: The ultra-fine nano silver particles synthesized by the fast Joule heating method can guide lithium to be uniformly deposited on the matrix material, thereby solving the problems existing when lithium metal is used as a negative electrode. The obtained Li negative electrode exhibited low voltage overpotential and excellent cycle stability without short circuit problems. The new rapid Joule heating method is also expected to create more possibilities for nano-fabrication of advanced energy storage materials.

Reference link: Ultrafine Silver Nanoparticles for Seeded Lithium Deposition toward Stable Lithium Metal Anode (Adv. Mater., 2017, DOI: 10.1002 / adma.201702714)

EES: double-layer garnet solid electrolyte skeleton structure

Professor Hu Liangbing Park campus of the University of Maryland and Eric Wachsman professor (co-author) first reported a new type of three-dimensional skeleton structure of a solid-state electrolyte, a hybrid type solid-state lithium batteries prepared from the solid electrolyte, with good safety performance and high energy density, etc. . In advanced lithium batteries, researchers have adopted a double-layered dense-porous garnet solid electrolyte framework structure, which simultaneously solves the two major problems of chemical / physical short circuit and electrode volume change. Although the dense layer is reduced to a thickness of a few micrometers, it still maintains good mechanical stability, thereby ensuring the safety of lithium metal batteries. The thick porous layer as a thin layer physical support can support a variety of positive electrode materials and provide ion conductance channels. The experiment found that the sulfur cathode load can reach> 7 mg / cm ² , and the hybrid Li-S battery has an initial coulomb efficiency of> 99.8% and an average coulomb efficiency of> 99% in subsequent cycles. This electrolyte skeleton structure shows a new lithium battery innovation strategy, and provides theoretical guidance for the research of all-solid-state batteries. The research results were titled " Three-Dimensional Bilayer Garnet Solid Electrolyte Based High Energy Density Lithium Metal-Sulfur Batteries " and published in the famous international journal Energy Environ. Sci .

Original link: Three-Dimensional Bilayer Garnet Solid Electrolyte Based High Energy Density Lithium Metal-Sulfur Batteries ( Energy Environ. Sci. , 2017, DOI: 10.1039 / C7EE01004D)

Angew. Chem. Int. Ed