Publications by authors named "Kunkun Guo"

High-voltage LiCoO is a promising cathode material for ultrahigh-energy lithium-ion batteries, particularly in the commercialization of 5G technology. However, achieving long-term operational stability remains a significant challenge. Herein, a quaterpolymer additive with multiple functional groups is introduced to enhance the electrochemical performance of LiCoO cathode at 4.

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LiNiMnO (LNMO), with its spinel symmetry, emerges as a promising cathode material for high-voltage lithium-ion batteries (LIBs). Nonetheless, the vulnerability of LNMO to interfacial degradation, particularly electrolyte breakdown during high-voltage operation, compromises its long-term cycling performance. To overcome this longstanding challenge, a slurry additive-polyester-urethane-acrylate (PEUA)-to form a multi-functional ultra-thin electrode coating, enhancing the lifespan and energy density of LIBs is introduced.

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Article Synopsis
  • A new method for creating poly(vinyl alcohol) (PVA) hydrogels uses supercooling and wet annealing to improve their strength and uniformity while keeping high water content.
  • * The technique involves dissolving PVA in hot water, rapidly cooling it to form ice crystals, and then replacing the ice with ethylene glycol (EG) to enhance polymer structure.
  • * The resulting hydrogels boast impressive mechanical properties, including high tensile strength and fracture toughness, making them more effective than traditional hydrogels for various applications.
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Rechargeable aqueous Zn-ion batteries (AZIBs) have been recognized as competitive devices for large-scale energy storage due to their characteristics of low cost, safe operation, and environmental friendliness. Nevertheless, their practical applications are greatly limited by zinc dendrite growth and side reactions occurring at the anode/electrolyte interface. Herein, we propose an effective and simple electrolyte engineering strategy, which is the introduction of l-lysine additive containing two amino groups and one carboxyl group into a ZnSO electrolyte to achieve stable and reversible Zn depositions.

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In this work, three dimensional (3D) self-supported Ni-FeOH@Ni-FeP needle arrays with core-shell heterojunction structure are fabricated via in situ hydroxide growth over Ni-FeP surface. The as-prepared electrodes show an outstanding oxygen evolution reaction (OER) performance, only requiring the low overpotential of 232 mV to reach 200 mA cm with the Tafel slop of 40 mV dec. For overall water splitting, an alkaline electrolyzer with these electrodes only requires a cell voltage of 2.

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Layered oxide cathode materials may undergo irreversible oxygen loss and severe phase transitions during high voltage cycling and may be susceptible to transition metal dissolution, adversely affecting their electrochemical performance. Here, to address these challenges, we propose synergistic doping of nonmetallic elements and in situ electrochemical diffusion as potential solution strategies. Among them, the distribution of the nonmetallic element fluorine within the material can be regulated by doping boron, thereby suppressing manganese dissolution through surface enrichment of fluorine.

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Structured passivation layers and hydrated Zn solvation structure strongly influence Zn depositions on Zn electrodes and then the cycle life and electrochemical performance of aqueous zinc ion batteries. To achieve these, the electrolyte additive of sodium L-ascorbate (Ass) is introduced into aqueous zinc sulfate (ZnSO, ZS) electrolyte solutions. Combined experimental characterizations with theoretical calculations, the unique passivation layers with vertical arrayed micro-nano structure are clearly observed, as well as the hydrated Zn solvation structure is changed by replacing two ligand water molecules with As, thus regulating the wettability and interfacial electric field intensity of Zn surfaces, facilitating rapid ionic diffusions within electrolytes and electrodes together with the inhibited side reactions and uniform depositions of Zn.

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A layered Li[NiCoMn]O (NCM)-based cathode is preferred for its high theoretical specific capacity. However, the two main issues that limit its practical application are severe safety issues and excessive capacity decay. A new electrode processing approach is proposed to synergistically enhance the electrochemical and safety performance.

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The crystal phase structure of cathode material plays an important role in the cell performance. During cycling, the cathode material experiences immense stress due to phase transformation, resulting in capacity degradation. Here, we show phase-engineered VO as an improved potassium-ion battery cathode; specifically, the amorphous VO exhibits superior K storage ability, while the crystalline M phase VO cannot even store K ions stably.

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As emerging energy storage devices, aqueous zinc ion batteries (AZIBs) with outstanding advantages of high safety, high energy density, and environmental friendliness have attracted much research interest. Herein, the favorable thornlike MnO micro-/nanostructures (PDA@MnO@NMC) are rationally constructed by the incorporation of both carbon substrates (NMC) and polydopamine (PDA) surface modifications. Ex situ X-ray diffraction and Raman characteristics show the formation of MnOOH and ZnMnO products, corresponding to H and Zn insertions in two discharge platforms.

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Increasing working voltage is a promising way to increase the energy density of lithium-ion batteries. Cycling and rate performance deteriorated due to excessive electrolyte decomposition and uncontrolled formation of a cathode-electrolyte interface (CEI) layer at a high voltage. A new concept is proposed to construct a high-voltage-stable electrode-electrolyte interface.

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Sequence plays a critical role in enabling unique properties and functions of natural biomolecules, which has promoted the rapid advancement of synthetic sequence-defined polymers in recent decades. Particularly, investigation of short chain sequence-defined oligomers (also called discrete oligomers) on their properties has become a hot topic. However, most studies have focused on discrete oligomers with conjugated structures.

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Gastrodin is the main active constituent of Tianma, a famous traditional Chinese herbal medicine. Our previous research has found that gastrodin is absorbed rapidly in the intestine by the sodium-dependent glucose transporter 1 (SGLT1). In the current report, gastrodin is the best glycoside compound absorbed via the glucose transport pathway.

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Objectives: The blocking effect of S-carvedilol (S-CAR) on the beta-adrenoceptor is about 100 times stronger than that of the right-handed conformation. However, further development is restricted because of its poor bioavailability caused by its low solubility and high first-pass effect. In the study, S-CAR self-microemulsifying drug-delivery systems (SMEDDSs) were established, and the effects of different lipid materials on the absorption and metabolism of S-CAR were investigated.

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Background: Glucose is the main energy component of cellular activities. However, as a polar molecule, glucose cannot freely pass through the phospholipid bilayer structure of the cell membrane. Thus, glucose must rely on specific transporters in the membrane.

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Vanadium nitride (VN) shows promising electrochemical properties as an energy storage devices electrode, specifically in supercapacitors. However, the pseudocapacitive charge storage in aqueous electrolytes shows mediocre performance. Herein, we judiciously demonstrate an impressive pseudocapacitor performance by hybridizing VN nanowires with pseudocapacitive 2D-layered MoS nanosheets.

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First-principles density functional theory calculations are first used to study possible reaction mechanisms of molybdenum carbide (MoC) as cathode catalysts in Li-CO batteries. By systematically investigating the Gibbs free energy changes of different intermediates during lithium oxalate (LiCO) and lithium carbonate (LiCO) nucleations, it is theoretically demonstrated that LiCO could be stabilized as the final discharge product, preventing the further formation of LiCO. The surface charge distributions of LiCO adsorbing onto catalytic surfaces are studied by using Bader charge analysis, given that electron transfers are found between LiCO and MoC surfaces.

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The rapid development of wearable electronics requires a revolution of power accessories regarding flexibility and energy density. The Li-CO battery was recently proposed as a novel and promising candidate for next-generation energy-storage systems. However, the current Li-CO batteries usually suffer from the difficulties of poor stability, low energy efficiency, and leakage of liquid electrolyte, and few flexible Li-CO batteries for wearable electronics have been reported so far.

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Liquid droplets on flat surfaces generally exhibit a contact angle in a range from 0 to [Formula: see text], but the two-phase interface within a vesicle membrane is very fascinating due to the involved force balance along three bending interfaces. Giant lipid vesicles encapsulated with the poly(ethylene glycol)/dextran aqueous two-phase system are established recently, and the phase interfaces within vesicle membrane are very interesting as experimentally observed. The developed theoretical framework by a combination of the Helfrich curvature elastic theory for vesicle membranes and self-consistent field theory for polymers has been extended to explore aqueous two phases within vesicles.

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Filamenting temperature-sensitive mutant Z (FtsZ), an essential cell division protein in bacteria, has recently emerged as an important and exploitable antibacterial target. The perturbation of FtsZ assembly is found to have an effect on cell cytokinesis and cell survival. Cell division time is an important physical parameter in cell cytokinesis.

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Hierarchically ordered mesoporous carbon/graphene (OMC/G) composites have been fabricated by means of a solvent-evaporation-induced self-assembly (EISA) method. The structures of these composites are characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy and nitrogen adsorption-desorption at 77 K. These results indicate that OMC/G composites possess the hierarchically ordered hexagonal p6mm mesostructure with the lattice unit parameter and pore diameter close to 10 nm and 3 nm, respectively.

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Cell morphodynamics during bacterial cytokinesis are theoretically explored by a combination of phase field model for rod-shaped cells and a kinetic description for FtsZ ring maintenance. The division times and cell shapes have been generally decided by the competition between the constriction forces generated by FtsZ rings and the curvature elastic energy for cells. The dependences of cell morphodynamics during bacterial cytokinesis on various kinetic rates of FtsZ filaments are focused in the present study.

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A biomimetic membrane in contact with several aqueous phases is theoretically studied using a combination of Helfrich curvature elasticity theory for fluid membranes and self-consistent field theory for polymers in solutions. Two phases that are thermodynamically formed by phase separation of aqueous solutions, as well as stable and metastable shapes of fluid vesicles, have been observed. The wetting transitions from complete to partial wetting and to complete dewetting are identified within a membrane compartment.

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Motivated by recent experiments, vesicles encapsulating two aqueous phases are theoretically explored using a combination of Helfrich curvature elasticity theory for fluid membranes and self-consistent field theory for polymers. The spatial distributions of two polymers, α and β, have been obtained, and two thermodynamic phases occur, as expected. Stable or metastable shapes of fluid and closed vesicles have also been achieved.

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Polymerization dynamics of single actin filaments coupled with adenosine triphosphate (ATP) hydrolysis is investigated via both theoretical analysis and Brownian dynamics simulations. Brownian dynamics simulations have been applied recently to study the growth behaviors of long filaments as a function of the free actin monomer concentrations, C(T), which is found to be in agreement with the associated experiments. In the present study, both ATP cap length and length diffusivity are studied as a function of the free ATP-actin monomer concentrations, C(T).

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