A Functional Air-Stable Li9.8GeP1.7Sb0.3S11.8I0.2 Superionic Conductor for High-Performance All-Solid-State Lithium Batteries.

Solid-state electrolytes (SSEs) based on sulfides have become a subject of great interest due to their superior Li-ion conductivity, low grain boundary resistance, and adequate mechanical strength. However, they grapple with chemical instability toward moisture hypersensitivity, which decreases their ionic conductivity, leading to more processing requirements. Herein, a Li9.8GeP1.7Sb0.3S11.8I0.2 (LGPSSI) superionic conductor is designed with a Li+ conductivity of 6.6 mS cm-1 and superior air stability based on hard and soft acids and bases (HSAB) theory. The introduction of optimal antimony (Sb) and iodine (I) into the Li10GeP2S12 (LGPS) structure facilitates fast Li-ion migration with low activation energy (Ea) of 20.33 kJ mol-1. The higher air stability of LGPSSI is credited to the strategic substitution of soft acid Sb into (Ge/P)S4 tetrahedral sites, examined by Raman and X-ray photoelectron spectroscopy techniques. Relatively lower acidity of Sb compared to phosphorus (P) realizes a stronger Sb-S bond, minimizing the evolution of toxic H2S (0.1728 cm3 g-1), which is ∼3 times lower than pristine LGPS when LGPSSI is exposed to moist air for 120 min. The NCA//Li-In full cell with a LGPSSI superionic conductor delivered the first discharge capacity of 209.1 mAh g-1 with 86.94% Coulombic efficiency at 0.1 mA cm-2. Furthermore, operating at a current density of 0.3 mA cm-2, LiNbO3@NCA/LGPSSI/Li-In cell demonstrated an exceptional reversible capacity of 117.70 mAh g-1, retaining 92.64% of its original capacity over 100 cycles.

An effective tellurium surface modification strategy to enhance the capacity and rate capability of Ni-rich LiNi0.8Co0.1Mn0.1O2 cathode material.

LiNi0.8Co0.1Mn0.1O2 (NCM) layered oxide is contemplated as an auspicious cathode candidate for commercialized lithium-ion batteries. Regardless, the successful commercial utilization of these materials is impeded by technical issues like structural degradation and poor cyclability. Elemental doping is among the most viable strategies for enhancing electrochemical performance. Herein, the preparation of surface tellurium-doped NCM is done by utilizing the methodology solid-state route at high temperatures. Surface doping of the Te ions leads to structural stability owing to the inactivation of oxygen at the surface via the binding of slabs of transition metal-oxygen. Remarkably, 1 wt% of Te doping in NCM exhibits enhanced electrochemical characteristics with an excellent discharge capacity, i.e., 225.8 mAh/g (0.1C), improved rate-capability of 156 mAh/g (5C) with 82.2% retention in capacity (0.5C) over 100 cycles within 2.7-4.3V as compared to all other prepared electrodes. Hence, the optimal doping of Te is favorable for enhancing capacity, cyclability along with rate capability of NCM.

Recent Advances in Transition Metal Tellurides (TMTs) and Phosphides (TMPs) for Hydrogen Evolution Electrocatalysis.

The hydrogen evolution reaction (HER) is a developing and promising technology to deliver clean energy using renewable sources. Presently, electrocatalytic water (H2O) splitting is one of the low-cost, affordable, and reliable industrial-scale effective hydrogen (H2) production methods. Nevertheless, the most active platinum (Pt) metal-based catalysts for the HER are subject to high cost and substandard stability. Therefore, a highly efficient, low-cost, and stable HER electrocatalyst is urgently desired to substitute Pt-based catalysts. Due to their low cost, outstanding stability, low overpotential, strong electronic interactions, excellent conductivity, more active sites, and abundance, transition metal tellurides (TMTs) and transition metal phosphides (TMPs) have emerged as promising electrocatalysts. This brief review focuses on the progress made over the past decade in the use of TMTs and TMPs for efficient green hydrogen production. Combining experimental and theoretical results, a detailed summary of their development is described. This review article aspires to provide the state-of-the-art guidelines and strategies for the design and development of new highly performing electrocatalysts for the upcoming energy conversion and storage electrochemical technologies.

Wearable and Flexible Multifunctional Sensor Based on Laser-Induced Graphene for the Sports Monitoring System.

The conversion of diverse polymeric substrates into laser-induced graphene (LIG) has recently emerged as a single-step method for the fabrication of patterned graphene-based wearable electronics with a wide range of applications in sensing, actuation, and energy storage. Laser-induced pyrolysis technology has many advantages over traditional graphene design: eco-friendly, designable patterning, roll-to-roll production, and controllable morphology. In this work, we designed wearable and flexible graphene-based strain and pressure sensors by laminating LIG from a commercial polyimide (PI) film. The as-prepared LIG was transferred onto a thin polydimethylsiloxane (PDMS) sheet, interwoven inside an elastic cotton sports fabric with the fabric glue as a wearable sensor. The single LIG/PDMS layer acts as a strain sensor, and a two-layer perpendicular stacking of LIG/PDMS (x and y laser-directed films) is designed for pressure sensing. This newly designed graphene textile (IGT) sensor performs four functions in volleyball sportswear, including volleyball reception detection, finger touch foul detection during blocking the ball from an opponent player, spike force measurements, and player position monitoring. An inexpensive sensor assists athletes in training and helps the coach formulate competition strategies.

An Unprecedented Fireproof, Anion-Immobilized Composite Electrolyte Obtained via Solidifying Carbonate Electrolyte for Safe and High-Power Solid-State Lithium-Ion Batteries.

The update of electrolytes from a liquid state to a solid state is considered effective in improving the safety and energy density of lithium-ion batteries (LIBs). Although numerous efforts have been made, solid-state electrolytes' (SSEs) insufficient charge transfer capability remains a significant obstruction to practical applications. Herein, a fireproof and anion-immobilized composite electrolyte is designed by solidifying carbonate electrolyte, exhibiting superior Li-ion conductivity (11.5 mS cm-1 at 30 °C) and Li-ion transference number (0.90), which endows LIBs excellent rate capability and cycling stability. Elaborate characteristics and theoretical calculations demonstrate the presence of robust anion-molecule coordination (composed of lithium bond and Coulomb force) enables a more efficient ion transport, where the mobility of Li+ ion is enhanced meanwhile the anions are immobilized. This work highlights how the strong interactions between electrolyte components can be used to simultaneously regulate the migration of Li+ ion and anion, and realize a one-step conversion of inflammable liquid-state electrolyte to nonflammable solid-state electrolyte.

Insight into the effects of dislocations in nanoscale titanium niobium oxide (Ti2Nb14O39) anode for boosting lithium-ion storage.

Defect engineering through induction of dislocations is an efficient strategy to design and develop an electrode material with enhanced electrochemical performance in energy storage technology. Yet, synthesis, comprehension, identification, and effect of dislocation in electrode materials for lithium-ion batteries (LIBs) are still elusive. Herein, we propose an ethanol-thermal method mediated with surfactant-template and subsequent annealing under air atmosphere to induce dislocation into titanium niobium oxide (Ti2Nb14O39), resultant nanoscale-dislocated-Ti2Nb14O39 (Nano-dl-TNO). High-resolution transmission electron microscope (HRTEM), fast Fourier transform (FFT), and Geometrical phase analysis (GPA) denote that the high dislocation density engraved with stacking faults forms into the Ti2Nb14O39 lattice. The presence of dislocation could offer an additional active site for lithium-ion storage and tune the electrical and ionic properties of the Ti2Nb14O39. The resultant Nano-dl-TNO delivers superior rate capability, high specific capacity, better cycling stability, and making Ti2Nb14O39 a suitable candidate among fast-charging anode materials for lithium-ion batteries. Moreover, In-situ High-resolution transmission electron microscope (HRTEM) and Geometrical phase analysis (GPA) evinces that the removal of the dislocated area in the Nano-dl-TNO leads to the contraction of the lattice, alleviation of the total volume expansion, causing the symmetrization and preserves structural stability. The present findings and designed approach reveal the rose-colored perspective of dislocation engineering into mixed transition metal oxides as next-generation anodes for advanced lithium-ion batteries and all-solid-state lithium-ion batteries.

Strong Interfacial Adhesion between the Li2S Cathode and a Functional Li7P2.9Ce0.2S10.9Cl0.3 Solid-State Electrolyte Endowed Long-Term Cycle Stability to All-Solid-State Lithium-Sulfur Batteries.

The extrinsic cathode interface between the sulfide electrolyte and the Li2S electrode is always ignored in all-solid-state lithium-sulfur batteries. However, the aggregation of the Li2S cathode is still observed during cycling. The gradually lost extrinsic contact interface between the cathode and the electrolyte would result in considerable interface resistance and severe capacity decay in the cell due to the lack of efficient electron and ionic conduction at the interface. Herein, a facile dual-doping strategy demonstrates the synthesis of a functional inorganic electrolyte. The obtained Li7P2.9Ce0.2S10.9Cl0.3 glass-ceramic electrolyte shows a higher-lithium-ionic conductivity of 3.2 mS cm-1 at room temperature. Further, UV-vis absorption and ex situ scanning electron microscopy studies confirm robust interfacial adhesion between the functional inorganic electrolyte, Li7P2.9Ce0.2S10.9Cl0.3, and the Li2S cathode. Thus, a stable extrinsic cathode interface is unprecedently built. Finally, the all-solid-state lithium-sulfur battery based on the Li7P2.9Ce0.2S10.9Cl0.3 electrolyte delivers a higher reversible initial capacity of 617 mA h g-1, a lower interface resistance of 25 Ω cm2 and much better cycling stability (with a high capacity retention of 89% after 100 cycles) than the pristine Li7P3S11 electrolyte.

Comparative Analysis of Ethylene/Diene Copolymerization and Ethylene/Propylene/Diene Terpolymerization Using Ansa-Zirconocene Catalyst with Alkylaluminum/Borate Activator: The Effect of Conjugated and Nonconjugated Dienes on Catalytic Behavior and Polymer Microstructure.

The copolymerization of ethylene‒diene conjugates (butadiene (BD), isoprene (IP) and nonconjugates (5-ethylidene-2-norbornene (ENB), vinyl norbornene VNB, 4-vinylcyclohexene (VCH) and 1, 4-hexadiene (HD)), and terpolymerization of ethylene-propylene-diene conjugates (BD, IP) and nonconjugates (ENB, VNB, VCH and HD) using two traditional catalysts of C2-symmetric metallocene-silylene-bridged rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2 (complex A) and ethylene-bridged rac-Et(Ind)2ZrCl2 (complex B)-with a [Ph3C][B(C6F5)4] borate/TIBA co-catalyst, were intensively studied. Compared to that in the copolymerization of ethylene diene, the catalytic activity was more significant in E/P/diene terpolymerization. We obtained a maximum yield of both metallocene catalysts with conjugated diene between 3.00 × 106 g/molMt·h and 5.00 × 106 g/molMt·h. ENB had the highest deactivation impact on complex A, and HD had the most substantial deactivation effect on complex B. A 1H NMR study suggests that dienes were incorporated into the co/ter polymers' backbone through regioselectivity. ENB and VNB, inserted by the edo double bond, left the ethylidene double bond intact, so VCH had an exo double bond. Complex A's methyl and phenyl groups rendered it structurally stable and exhibited a dihedral angle greater than that of complex B, resulting in 1, 2 isoprene insertion higher than 1, 4 isoprene that is usually incapable of polymerization coordination. High efficiency in terms of co- and ter- monomer incorporation with higher molecular weight was found for complex 1. The rate of incorporation of ethylene and propylene in the terpolymer backbone structure may also be altered by the conjugated and nonconjugated dienes. 13C-NMR, 1H-NMR, and GPC techniques were used to characterize the polymers obtained.

Kinetic and Thermal Study of Ethylene and Propylene Homo Polymerization Catalyzed by ansa-Zirconocene Activated with Alkylaluminum/Borate: Effects of Alkylaluminum on Polymerization Kinetics and Polymer Structure.

The kinetics of ethylene and propylene polymerization catalyzed by homogeneous metallocene were investigated using 2-thiophenecarbonyl chloride followed by quenched-flow methods. The studied metallocene catalysts are: rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2 (Mt-I), rac-Et(Ind)2ZrCl2 (Mt-II) activated with ([Me2NPh][B(C6F5)4] (Borate-I), [Ph3C][B(C6F5)4] (Borate-II), and were co-catalyzed with different molar ratios of alkylaluminum such as triethylaluminium (TEA) and triisobutylaluminium (TIBA). The change in molecular weight, molecular weight distribution, microstructure and thermal properties of the synthesized polymer are discussed in detail. Interestingly, both Mt-I and Mt-II showed high activity in polyethylene with productivities between 3.17 × 106 g/molMt·h to 5.06 × 106 g/molMt·h, activities were very close to each other with 100% TIBA, but Mt-II/borate-II became more active when TEA was more than 50% in cocatalyst. Similarly, Polypropylene showed the highest activity of 11.07 106 g /molMt·h with Mt-I/Borate-I/TIBA. The effects of alkylaluminum on PE molecular weight were much more complicated; MWD curve changed from mono-modal in Mt-I/borate-I/TIBA to bimodal type when TIBA was replaced by different amounts of TEA. In PE, the active center fractions [C*]/[Zr] of Mt-I/borate were higher than that of Mt-II/borate and average chain propagation rate constant (k p) value slightly decreased with the increase of TEA/TIBA ratio, but the Mt-II/borate systems showed higher k p 1007 k p (L/mol·s). In PP, the Mt-I/borate presented much higher [C*]/[Zr] and k p value than the Mt-II. This work also extend to investigate the mechanistic features of zirconocenes catalyzed olefin polymerizations that addressed the largely unknown issues in zirconocenes in the distribution of the catalyst, between species involved in polymer chain growth and dormant state. In both metallocene systems, chain transfer with alkylaluminum is the dominant way of chain termination. To understand the mechanism of cocatalyst effects on PE Mw and (MWD), the unsaturated chain ends formed via ß-H transfer have been investigated by 1H NMR analysis.

Chickpea derived Co nanocrystal encapsulated in 3D nitrogen-doped mesoporous carbon: Pressure cooking synthetic strategy and its application in lithium-sulfur batteries.

Lithium-sulfur batteries, as a next-generation energy storage system, could deliver much higher energy density than traditional lithium-ion batteries. Although many scientific issues have been well solved, the low-cost and green synthesis of the sulfur host to realize efficient electrochemical conversions between polysulfides and sulfur needs more consideration for commercial application. Herein, Co nanocrystal encapsulated in 3D nitrogen-doped mesoporous carbon (Co@NC) is produced in gram-scale via a simple pressure-cooking strategy by using biomass as raw material. The heterogeneous catalyst was featured by an oval morphology consisting of a tremendous amount of mesopores. The Co nanocrystals in the 3D mesoporous carbon could promote the confinement and fast conversion of polysulfides; simultaneously, the 3D hollow oval morphologies could not only substantially relieve the volume change of the cathode part but also enhance the lithium-ion transportation. Consequently, a sulfur cathode within Co@NC with a sulfur loading of 2.5 mg/cm2 exhibits significantly improved cycle stability with a fade of 0.17% per cycle over 200 cycles. Our works prove the beneficial effects of heterogeneous catalysis in polysulfide conversion reactions and provide a green, facile, scalable, and low-cost synthetic strategy of advanced hollow carbon monolith for high-performance Li-S batteries.

Enhanced Air Stability and High Li-Ion Conductivity of Li6.988P2.994Nb0.2S10.934O0.6 Glass-Ceramic Electrolyte for All-Solid-State Lithium-Sulfur Batteries.

The development of novel sulfide solid-state electrolytes with high Li-ion conductivity, excellent air-stability, and a stable electrode-electrolyte interface is needed for the commercialization of all-solid-state cells. Currently, an ideal solid electrolyte, which can integrate the solid-state batteries, has not been developed. Herein, the Nb and O codoping strategy is excogitated to improve the chemical and electrochemical performance of sulfide electrolytes. The interactive effect of Nb and O in the novel Li6.988P2.994Nb0.2S10.934O0.6 glass-ceramic electrolyte results in a superior Li+ conductivity of 2.82 mS cm-1 and remarkable air-stability and electrochemical stability against the Li metal compared to the Li7P3S11 counterpart at 25 °C. Solid-state 31P MAS-NMR revealed that doping of LiNbO3 (0 ≤ x ≤ 1) not only enhances the degree of crystallization but also produces P2OS64- units with bridging oxygen atoms in the Li6.988P2.994Nb0.2S10.934O0.6 glass-ceramic electrolyte and hence boosts the conductive deportment of glass-ceramics. Impressively, the developed electrolyte exhibits a stable full voltage window of up to 5 V versus Li/Li+. Furthermore, electrochemical impedance spectroscopy analysis shows that the interface resistance of the Li2S/Li6.988P2.994Nb0.2S10.934O0.6/Li-In cell is lower than that of the cell with Li7P3S11 electrolyte. Besides, the battery of the Li6.988P2.994Nb0.2S10.934O0.6 electrolyte delivers initial discharge capacities of 472.7 and 530.9 mAh g-1 after 50 cycles with 98.88% capacity retention from the second cycle. The Coulombic efficiency of the cell remains at ∼100% after 50 cycles. Thus, the proposed codoped strategy produced a sulfide electrolyte, which addressed the challenging issues of chemical/electrochemical stabilities and showed promising industrial prospects for next-generation all-solid-state batteries.