Capacity recovery by transient voltage pulse in silicon-anode batteries.

In the quest for high-capacity battery electrodes, addressing capacity loss attributed to isolated active materials remains a challenge. We developed an approach to substantially recover the isolated active materials in silicon electrodes and used a voltage pulse to reconnect the isolated lithium-silicon (LiSi) particles back to the conductive network. Using a 5-second pulse, we achieved >30% of capacity recovery in both Li-Si and Si-lithium iron phosphate (Si-LFP) batteries.

Electrified -Freezing of Electrocatalytic CO Reduction Cells for Cryogenic Electron Microscopy.

The ability to freeze and stabilize reaction intermediates in their metastable states and obtain their structural and chemical information with high spatial resolution is critical to advance materials technologies such as catalysis and batteries. Here, we develop an electrified -freezing methodology to preserve these metastable states under electrochemical reaction conditions for cryogenic electron microscopy (cryo-EM) imaging and spectroscopy. Using Cu catalysts for CO reduction as a model system, we observe restructuring of the Cu catalyst in a CO atmosphere while the same catalyst remains intact in air at the nanometer scale.

Tunable 1D and 2D Polyacrylonitrile Nanosheet Superstructures.

Carbon superstructures are widely applied in energy and environment-related areas. Among them, the flower-like polyacrylonitrile (PAN)-derived carbon materials have shown great promise due to their high surface area, large pore volume, and improved mass transport. In this work, we report a versatile and straightforward method for synthesizing one-dimensional (1D) nanostructured fibers and two-dimensional (2D) nanostructured thin films based on flower-like PAN chemistry by taking advantage of the nucleation and growth behavior of PAN.

Colorful low-emissivity paints for space heating and cooling energy savings.

Space heating and cooling consume ~13% of global energy every year. The development of advanced materials that promote energy savings in heating and cooling is gaining increasing attention. To thermally isolate the space of concern and minimize the heat exchange with the outside environment has been recognized as one effective solution.

Prelithiation by Direct Integration of Lithium Mesh into Battery Cells.

Silicon (Si)-based anodes are promising for next-generation lithium (Li)-ion batteries due to their high theoretical capacity (∼3600 mAh/g). However, they suffer quantities of capacity loss in the first cycle from initial solid electrolyte interphase (SEI) formation. Here, we present an prelithiation method to directly integrate a Li metal mesh into the cell assembly.

An Integrated 3D Hydrophilicity/Hydrophobicity Design for Artificial Sweating Skin (i-TRANS) Mimicking Human Body Perspiration.

Artificial skins reproducing properties of human skin are emerging and significant for study in various areas, such as robotics, medicine, and textiles. Perspiration, as one of the most imperative thermoregulation functions of human skin, is gaining increasing attention, but how to realize ideal artificial skin for perspiration simulation remains challenging. Here, an integrated 3D hydrophilicity/hydrophobicity design is proposed for artificial sweating skin (i-TRANS).

A scalable solid-state nanoporous network with atomic-level interaction design for carbon dioxide capture.

Carbon capture and sequestration reduces carbon dioxide emissions and is critical in accomplishing carbon neutrality targets. Here, we demonstrate new sustainable, solid-state, polyamine-appended, cyanuric acid-stabilized melamine nanoporous networks (MNNs) via dynamic combinatorial chemistry (DCC) at the kilogram scale toward effective and high-capacity carbon dioxide capture. Polyamine-appended MNNs reaction mechanisms with carbon dioxide were elucidated with double-level DCC where two-dimensional heteronuclear chemical shift correlation nuclear magnetic resonance spectroscopy was performed to demonstrate the interatomic interactions.

Cold-Starting All-Solid-State Batteries from Room Temperature by Thermally Modulated Current Collector in Sub-Minute.

All-solid-state batteries (ASSBs) show great potential as high-energy and high-power energy-storage devices but their attainable energy/power density at room temperature is severely reduced because of the sluggish kinetics of lithium-ion transport. Here a thermally modulated current collector (TMCC) is reported, which can rapidly cold-start ASSBs from room temperature to operating temperatures (70-90 °C) in less than 1 min, and simultaneously enhance the transient peak power density by 15-fold compared to one without heating. This TMCC is prepared by integrating a uniform, ultrathin (≈200 nm) nickel layer as a thermal modulator within an ultralight polymer-based current collector.

Integrated cooling (i-Cool) textile of heat conduction and sweat transportation for personal perspiration management.

Perspiration evaporation plays an indispensable role in human body heat dissipation. However, conventional textiles tend to focus on sweat removal and pay little attention to the basic thermoregulation function of sweat, showing limited evaporation ability and cooling efficiency in moderate/profuse perspiration scenarios. Here, we propose an integrated cooling (i-Cool) textile with unique functional structure design for personal perspiration management.

Integration of daytime radiative cooling and solar heating for year-round energy saving in buildings.

The heating and cooling energy consumption of buildings accounts for about 15% of national total energy consumption in the United States. In response to this challenge, many promising technologies with minimum carbon footprint have been proposed. However, most of the approaches are static and monofunctional, which can only reduce building energy consumption in certain conditions and climate zones.

Designing hierarchical nanoporous membranes for highly efficient gas adsorption and storage.

Nanoporous membranes with two-dimensional materials such as graphene oxide have attracted attention in volatile organic compounds (VOCs) and H adsorption because of their unique molecular sieving properties and operational simplicity. However, agglomeration of graphene sheets and low efficiency remain challenging. Therefore, we designed hierarchical nanoporous membranes (HNMs), a class of nanocomposites combined with a carbon sphere and graphene oxide.

Supercooled liquid sulfur maintained in three-dimensional current collector for high-performance Li-S batteries.

In lithium-sulfur (Li-S) chemistry, the electrically/ionically insulating nature of sulfur and LiS leads to sluggish electron/ion transfer kinetics for sulfur species conversion. Sulfur and LiS are recognized as solid at room temperature, and solid-liquid phase transitions are the limiting steps in Li-S batteries. Here, we visualize the distinct sulfur growth behaviors on Al, carbon, Ni current collectors and demonstrate that (i) liquid sulfur generated on Ni provides higher reversible capacity, faster kinetics, and better cycling life compared to solid sulfur; and (ii) Ni facilitates the phase transition (e.

Theoretical Calculation Guided Design of Single-Atom Catalysts toward Fast Kinetic and Long-Life Li-S Batteries.

Lithium-sulfur (Li-S) batteries are promising next-generation energy storage technologies due to their high theoretical energy density, environmental friendliness, and low cost. However, low conductivity of sulfur species, dissolution of polysulfides, poor conversion from sulfur reduction, and lithium sulfide (LiS) oxidation reactions during discharge-charge processes hinder their practical applications. Herein, under the guidance of density functional theory calculations, we have successfully synthesized large-scale single atom vanadium catalysts seeded on graphene to achieve high sulfur content (80 wt % sulfur), fast kinetic (a capacity of 645 mAh g at 3 C rate), and long-life Li-S batteries.

Spectrally Selective Nanocomposite Textile for Outdoor Personal Cooling.

Outdoor heat stress poses a serious public health threat and curtails industrial labor supply and productivity, thus adversely impacting the wellness and economy of the entire society. With climate change, there will be more intense and frequent heat waves that further present a grand challenge for sustainability. However, an efficient and economical method that can provide localized outdoor cooling of the human body without intensive energy input is lacking.

A dual-mode textile for human body radiative heating and cooling.

Maintaining human body temperature is one of the most basic needs for living, which often consumes a huge amount of energy to keep the ambient temperature constant. To expand the ambient temperature range while maintaining human thermal comfort, the concept of personal thermal management has been recently demonstrated in heating and cooling textiles separately through human body infrared radiation control. Realizing these two opposite functions within the same textile would represent an exciting scientific challenge and a significant technological advancement.

Warming up human body by nanoporous metallized polyethylene textile.

Space heating accounts for the largest energy end-use of buildings that imposes significant burden on the society. The energy wasted for heating the empty space of the entire building can be saved by passively heating the immediate environment around the human body. Here, we demonstrate a nanophotonic structure textile with tailored infrared (IR) property for passive personal heating using nanoporous metallized polyethylene.

Radiative human body cooling by nanoporous polyethylene textile.

Thermal management through personal heating and cooling is a strategy by which to expand indoor temperature setpoint range for large energy saving. We show that nanoporous polyethylene (nanoPE) is transparent to mid-infrared human body radiation but opaque to visible light because of the pore size distribution (50 to 1000 nanometers). We processed the material to develop a textile that promotes effective radiative cooling while still having sufficient air permeability, water-wicking rate, and mechanical strength for wearability.