N-doped 3D carbon encapsulating nickel selenide nanoarchitecture with cation defect engineering: An ultrafast and long-life anode for sodium-ion batteries.

Transition metal chalcogenides (TMCs) hold great potential for sodium-ion batteries (SIBs) owing to their multielectron conversion reactions, yet face challenges of poor intrinsic conductivity, sluggish diffusion kinetics, severe phase transitions, and structural collapse during cycling. Herein, a self-templating strategy is proposed for the synthesis of a class of metal cobalt-doped NiSe nanoparticles confined within three-dimensional (3D) N-doped macroporous carbon matrix nanohybrids (Co-NiSe/NMC). The cation defect engineering within the developed Co-NiSe and 3D N-doped carbon plays a crucial role in enhancing intrinsic conductivity, reinforcing structural stability, and reducing the barrier to sodium ion diffusion, which are verified by a series of electrochemical kinetic analyses and density functional theory calculations. Significantly, such cation defect engineering not only reduces overpotential but also accelerates conversion reaction kinetics, ensuring both exceptional high-rate capability and extended durability. Consequently, the optimally engineered Co-NiSe/NMC demonstrates a remarkable rate performance, delivering 390 mAh g-1 at 10 A g-1. Moreover, it exhibits an unprecedented lifespan, maintaining a remarkable capacity of 403 mAh g-1 after 1400 cycles and 318 mAh g-1 after 4000 cycles, even at high rates of 1.0 and 2.0 A g-1, respectively. This work marks a substantial advancement in achieving both high performance and prolonged cycle life in sodium-ion batteries.

Tunneling Interpenetrative Lithium Ion Conduction Channels in Polymer-in-Ceramic Composite Solid Electrolytes.

Polymer-in-ceramic composite solid electrolytes (PIC-CSEs) provide important advantages over individual organic or inorganic solid electrolytes. In conventional PIC-CSEs, the ion conduction pathway is primarily confined to the ceramics, while the faster routes associated with the ceramic-polymer interface remain blocked. This challenge is associated with two key factors: (i) the difficulty in establishing extensive and uninterrupted ceramic-polymer interfaces due to ceramic aggregation; (ii) the ceramic-polymer interfaces are unresponsive to conducting ions because of their inherent incompatibility. Here, we propose a strategy by introducing polymer-compatible ionic liquids (PCILs) to mediate between ceramics and the polymer matrix. This mediation involves the polar groups of PCILs interacting with Li+ ions on the ceramic surfaces as well as the interactions between the polar components of PCILs and the polymer chains. This strategy addresses the ceramic aggregation issue, resulting in uniform PIC-CSEs. Simultaneously, it activates the ceramic-polymer interfaces by establishing interpenetrating channels that promote the efficient transport of Li+ ions across the ceramic phase, the ceramic-polymer interfaces, and the intervening pathways. Consequently, the obtained PIC-CSEs exhibit high ionic conductivity, exceptional flexibility, and robust mechanical strength. A PIC-CSE comprising poly(vinylidene fluoride) (PVDF) and 60 wt % PCIL-coated Li3Zr2Si2PO12 (LZSP) fillers showcasing an ionic conductivity of 0.83 mS cm-1, a superior Li+ ion transference number of 0.81, and an elongation of ∼300% at 25 °C could be produced on meter-scale. Its lithium metal pouch cells show high energy densities of 424.9 Wh kg-1 (excluding packing films) and puncture safety. This work paves the way for designing PIC-CSEs with commercial viability.

Effects of Li+ conduction on the capacity utilization of cathodes in all-solid-state lithium batteries.

Li+ conduction in all-solid-state lithium batteries is limited compared with that in lithium-ion batteries based on liquid electrolytes because of the lack of an infiltrative network for Li+ transportation. Especially for the cathode, the practically available capacity is constrained due to the limited Li+ diffusivity. In this study, all-solid-state thin-film lithium batteries based on LiCoO2 thin films with varying thicknesses were fabricated and tested. To guide the cathode material development and cell design of all-solid-state lithium batteries, a one-dimensional model was utilized to explore the characteristic size for a cathode with varying Li+ diffusivity that would not constrain the available capacity. The results indicated that the available capacity of cathode materials was only 65.6% of the expected value when the area capacity was as high as 1.2 mAh/cm2. The uneven Li distribution in cathode thin films owing to the restricted Li+ diffusivity was revealed. The characteristic size for a cathode with varying Li+ diffusivity that would not constrain the available capacity was explored to guide the cathode material development and cell design of all-solid-state lithium batteries.

Confined WS2 Nanosheets Tubular Nanohybrid as High-Kinetic and Durable Anode for Sodium-Based Dual Ion Batteries.

Sodium based dual-ion battery (SDIB) has been regarded as one of the promising batteries technologies thanks to its high working voltage and natural abundance of sodium source, its practical application yet faces critical issues of low capacity and sluggish kinetics of intercalation-type graphite anode. Here, a tubular nanohybrid composed of building blocks of carbon-film wrapped WS2 nanosheets on carbon nanotube (WS2 /C@CNTs) was reported. The expanded (002) interlayer and dual-carbon confined structure endowed WS2 nanosheets with fast charge transportation and excellent structural stability, and thus WS2 /C@CNTs showed highly attractive electrochemical properties for Na+ storage with high reversible capacity, fast kinetic, and robust durability. The full sodium-based dual ion batteries by coupling WS2 /C@CNTs anode with graphite cathode full cell presented a high reversible capacity (210 mAh g-1 at 0.1 A g-1 ), and excellent rate performance with a high capacity of 137 mAh g-1 at 5.0 A g-1 .

Characterization of a novel detergent-resistant type I pullulanase from Bacillus megaterium Y103 and its application in laundry detergent.

This study aims to find a moderate pullulanase for detergent industry. The pulY103B gene (2217 bp) from Bacillus megaterium Y103 was cloned and expressed in Escherichia coli. PulY103B contained four conserved regions of glycoside hydrolase family (GH) 13 and the typical sequence of type I pullulanase. The optimal reaction conditions of PulY103B were pH 6.5 and 40 °C. In addition, it remained stable below 40 °C and over 80% of activity was retained at pH ranging from 6.0 to 8.5. The best substrate for the enzyme was pullulan. Furthermore, it exhibited activity toward wheat starch (36.5%) and soluble starch (33.4%) but had no activity toward amylose and glycogen. Maltotriose and maltohexaose were major pullulan hydrolysis products. Soluble starch and amylopectin were mainly hydrolyzed into maltotetraose. These results indicated that PulY103B is a novel type I pullulanase with transglycosylation activity via formation of α-1,4-glucosidic linkages. Moreover, PulY103B was strongly stimulated by nonionic detergents [viz, Tween 20 (10%), Tween 80 (1%), Triton X-100 (20%)] and commercial liquid detergents (3.0 g/L). Wash performance tests demonstrated that the mixture of PulY103B and detergent removed starch-based stains better than using detergent alone (p < 0.05). Therefore, this pullulanase has big potential as a detergent additive.

Effect of alginate coatings incorporated with chitinase from 'Baozhu' pear on the preservation of cherry tomato during refrigerated storage.

The effects of edible coatings based on sodium alginate with 'Baozhu' pear chitinase on the quality of cherry tomatoes during refrigerated storage were evaluated. Cherry tomatoes inoculated with Fusarium oxysporum were coated and stored up to 21 days. All coatings with the chitinase significantly reduced F. oxysporum proliferation on cherry tomatoes during storage and extended the shelf life of cherry tomatoes effectively (p < .05). Results showed that alginate coatings with the chitinase could prevent weight loss, maintain firmness, and slow down the changes of titratable acidity and vitamin C (p < .05) in a dose-dependent manner. However, no significant differences were observed between T3 (1% alginate/0.15% 'Baozhu' pear chitinase/1% glycerin) and T4 (1% sodium alginate/0.3% 'Baozhu' pear chitinase/1% glycerin) (p > .05). Overall, alginate coating with 0.15% 'Baozhu' pear chitinase could be a promising method to maintain the quality of cherry tomatoes.

Enhancing ionic conductivity in solid electrolyte by relocating diffusion ions to under-coordination sites.

Solid electrolytes are highly important materials for improving safety, energy density, and reversibility of electrochemical energy storage batteries. However, it is a challenge to modulate the coordination structure of conducting ions, which limits the improvement of ionic conductivity and hampers further development of practical solid electrolytes. Here, we present a skeleton-retained cationic exchange approach to produce a high-performance solid electrolyte of Li3Zr2Si2PO12 stemming from the NASICON-type superionic conductor of Na3Zr2Si2PO12. The introduced lithium ions stabilized in under-coordination structures are facilitated to pass through relatively large conduction bottlenecks inherited from the Na3Zr2Si2PO12 precursor. The synthesized Li3Zr2Si2PO12 achieves a low activation energy of 0.21 eV and a high ionic conductivity of 3.59 mS cm-1 at room temperature. Li3Zr2Si2PO12 not only inherits the satisfactory air survivability from Na3Zr2Si2PO12 but also exhibits excellent cyclic stability and rate capability when applied to solid-state batteries. The present study opens an innovative avenue to regulate cationic occupancy and make new materials.

TiO2 Nanofiber-Modified Lithium Metal Composite Anode for Solid-State Lithium Batteries.

Solid-state lithium metal batteries (SSLMBs), using lithium metal as the anode and garnet-structured Li6.5La3Zr1.5Ta0.5O12 (LLZTO) as the electrolyte, are attractive and promising due to their high energy density and safety. However, the interface contact between the lithium metal and LLZTO is a major obstacle to the performance of SSLMBs. Here, we successfully improve the interface wettability by introducing one-dimensional (1D) TiO2 nanofibers into the lithium metal to obtain a Li-lithiated TiO2 composite anode (Li-TiO2). When 10 wt % TiO2 nanofibers are added, the formed composite anode offers a seamless interface contact with LLZTO and enables an interfacial resistance of 27 Ω cm2, which is much smaller than 374 Ω cm2 of pristine lithium metal. Due to the enhanced interface wettability, the symmetric Li-TiO2|LLZTO|Li-TiO2 cell upgrades the critical current density to 2.2 mA cm-2 and endures stable cycling over 550 h. Furthermore, by coupling the Li-TiO2 composite anode with the LiFePO4 cathode, the full cell shows stable cycling performance. This work proves the role of TiO2 nanofibers in enhancing the interface contact between the garnet electrolyte and the lithium metal anode and improving the performance of SSLMBs and provides an effective approach with 1D additives for solving the interface issues.

Li/Garnet Interface Optimization: An Overview.

Solid-state lithium batteries can improve the safety and energy density of the present liquid-electrolyte-based lithium-ion batteries. To achieve this goal, both solid electrolyte and lithium anode technology are the keys. Lithium garnet is a promising electrolyte to enable the next generation solid-state lithium batteries due to its high ionic conductivity, good chemical, and electrochemical stability, and easiness to scale up. It is relatively stable against Li metal but the poor contact area and the presence of resistive impurity or decomposition layers at the interface interfere with fast charge transfer, thereby, spiking the interfacial resistance, overpotential, local current density, and the propensity for dendrite growth. In this Review, we first summarize the recent understanding of the interfacial problems at the Li/garnet interface from both computational and experimental viewpoints while seizing the opportunity to shed light on the chemical/electrochemical stability of garnet against Li metal anode. Also, we highlight various interface optimization strategies that have been demonstrated to be effective in improving the interface performance. We conclude this Review with a few suggestions as guides for future work.

Preparation of Nanocomposite Polymer Electrolyte via In Situ Synthesis of SiO2 Nanoparticles in PEO.

Composite polymer electrolytes provide an emerging solution for new battery development by replacing liquid electrolytes, which are commonly complexes of polyethylene oxide (PEO) with ceramic fillers. However, the agglomeration of fillers and weak interaction restrict their conductivities. By contrast with the prevailing methods of blending preformed ceramic fillers within the polymer matrix, here we proposed an in situ synthesis method of SiO2 nanoparticles in the PEO matrix. In this case, robust chemical interactions between SiO2 nanoparticles, lithium salt and PEO chains were induced by the in situ non-hydrolytic sol gel process. The in situ synthesized nanocomposite polymer electrolyte delivered an impressive ionic conductivity of ~1.1 × 10-4 S cm-1 at 30 °C, which is two orders of magnitude higher than that of the preformed synthesized composite polymer electrolyte. In addition, an extended electrochemical window of up to 5 V vs. Li/Li+ was achieved. The Li/nanocomposite polymer electrolyte/Li symmetric cell demonstrated a stable long-term cycling performance of over 700 h at 0.01-0.1 mA cm-2 without short circuiting. The all-solid-state battery consisting of the nanocomposite polymer electrolyte, Li metal and LiFePO4 provides a discharge capacity of 123.5 mAh g-1, a Coulombic efficiency above 99% and a good capacity retention of 70% after 100 cycles.

Highly Adhesive Li-BN Nanosheet Composite Anode with Excellent Interfacial Compatibility for Solid-State Li Metal Batteries.

Solid-state lithium metal batteries (SSLMBs) are promising energy storage devices by employing lithium metal anodes and solid-state electrolytes (SSEs) to offer high energy density and high safety. However, their efficiency is limited by Li metal/SSE interface barriers, including insufficient contact area and chemical/electrochemical incompatibility. Herein, a strategy to effectively improve the adhesiveness of Li metal to garnet-type SSE is proposed by adding only a few two-dimensional boron nitride nanosheets (BNNS) (5 wt %) into Li metal by triggering the transition from point contact to complete adhesion between Li metal and ceramic SSE. The interface between the Li-BNNS composite anode and the garnet exhibits a low interfacial resistance of 9 Ω cm2, which is significantly lower than that of bare Li/garnet interface (560 Ω cm2). Furthermore, the enhanced contact and the additional BNNS in the interface act synergistically to offer a high critical current density of 1.5 mA/cm2 and a stable electrochemical plating/striping over 380 h. Moreover, the full cell paired with the Li-BNNS composite anode and the LiFePO4 cathode shows stable cycling performance at room temperature. Our results introduce an appealing composite strategy with two-dimensional materials to overcome the interface challenges, which provide more opportunities for the development of SSLMBs.

Dual Substitution and Spark Plasma Sintering to Improve Ionic Conductivity of Garnet Li7La3Zr2O12.

Garnet Li7La3Zr2O12 is one of the most promising solid electrolytes used for solid-state lithium batteries. However, low ionic conductivity impedes its application. Herein, we report Ta-doping garnets with compositions of Li7-xLa3Zr2-xTaxO12 (0.1 ≤ x ≤ 0.75) obtained by solid-state reaction and free sintering, which was facilitated by graphene oxide (GO). Furthermore, to optimize Li6.6La3Zr1.6Ta0.4O12, Mg2+ was select as a second dopant. The dual substitution of Ta5+ for Zr4+ and Mg2+ for Li+ with a composition of Li6.5Mg0.05La3Zr1.6Ta0.4O12 showed an enhanced total ionic conductivity of 6.1 × 10-4 S cm-1 at room temperature. Additionally, spark plasma sintering (SPS) was applied to further densify the garnets and enhance their ionic conductivities. Both SPS specimens present higher conductivities than those produced by the conventional free sintering. At room temperature, the highest ionic conductivity of Li6.5Mg0.05La3Zr1.6Ta0.4O12 sintered at 1000 °C is 8.8 × 10-4 S cm-1, and that of Li6.6La3Zr1.6Ta0.4O12 sintered at 1050 °C is 1.18 × 10-3 S cm-1.

Association of lower leukocyte count before thrombolysis with early neurological improvement in acute ischemic stroke patients.

Early neurological improvement (ENI) after thrombolysis in acute ischemic stroke is associated with a favorable long-term outcome. With the goal to evaluate ENI, we aimed to investigate whether ENI bears a relationship with routine blood tests before thrombolysis. A total of 240 patients with confirmed early ischemic stroke and intravenous recombinant tissue plasminogen activator (rtPA) treatment were enrolled from two teaching hospitals, between June 2010 and March 2016. The primary endpoint was ENI that was defined as a decrease of National Institutes of Health Stroke Scale (NIHSS) scores ≥4 points or complete recovery in 24 h after thrombolysis. Patients underwent NIHSS score evaluation and head CT scan before and after 24 h of IV rtPA treatment. Blood samples for routine blood tests were drawn at admission before IV rtPA administration. Multivariate regression analysis was used to explore the relationship between test results and ENI. Of the results of routine blood tests, leukocyte count before thrombolysis was found to associated independently with ENI (adjusted odds ratio[adjOR] = 0.894, P = 0.025, 95% CI = 0.810-0.986). Onset-to-treatment time (OTT; adjOR = 0.993, P = 0.003, 95% CI = 0.988-0.997) and negative CT sign (adjOR = 3.975, P < 0.001, 95% CI = 1.916-8.246) both were associated with ENI. The change of NIHSS score after 24 h of thrombolysis correlated with the leukocyte and neutrophil count, and neutrophil-to-lymphocyte ratio. A model that combined leukocyte count, positive CT sign, and OTT was generated to predict non-ENI (AUC = 0.717). Therefore, we determined that the leukocyte count was independently associated with ENI. Predicting non-ENI aid in selecting patients for mechanical thrombectomy after thrombolysis.

Well-ordered mesoporous Fe2O3/C composites as high performance anode materials for sodium-ion batteries.

Sodium-ion batteries have attracted considerable attention in recent years. In order to promote the practical application of sodium-ion batteries, the electrochemical performances, such as specific capacity, reversibility, and rate capability of the anode materials, should be further improved. In this work, a Fe2O3/C composite with a well-ordered mesoporous structure is prepared via a facile co-impregnation method by using mesoporous silica SBA-15 as a hard template. When used as an anode material for sodium-ion batteries, the well-ordered mesoporous structure ensures fast mass transport kinetics. The presence of nano-sized Fe2O3 particles confined within the carbon walls significantly enhances the specific capacity of the composite. The carbon walls in the composite act not only as an active material contributing to the specific capacity, but also as a conductive matrix improving the cycling stability of Fe2O3 nanoparticles. As a result, the well-ordered mesoporous Fe2O3/C composite exhibits high specific capacity, excellent cycleability, and high rate capability. It is proposed that this simple co-impregnation method is applicable for the preparation of well-ordered mesoporous transition oxide/carbon composite electrode materials for high performance sodium-ion and lithium-ion batteries.

One-Step Synthesis of MnO2 Flower/Carbon Nanotube with Improved Lithium Storage Properties.

This work reports a one-step hydrothermal synthesis of MnO2-flower/Carbon nanotube (CNTs) binary material, featuring a coated-worm like structure. The material showed a specific capacity of 800 mA h g(-1), a working plateau at 0.5 V against a Li+/Li electrode, and ideal stability under a current density of 2 A g(-1). The transition of the crystalline form of MnO2 was also observed when adjusting the ratio of CNTs in the reaction, which may be an intriguing result for the material's future application.

Carbon coated MnO@Mn3N2 core-shell composites for high performance lithium ion battery anodes.

Carbon coated MnO@Mn(3)N(2) core-shell composites (MnO@Mn(3)N(2)/C) were synthesized in a simple approach by calcining MnO(2) nanowires with urea at 800 °C under an ammonia atmosphere. Urea derived carbon nanosheets were partially coated on pure phase MnO@Mn(3)N(2) core-shell composites. Electrochemical measurements reveal that the MnO@Mn(3)N(2)/C displayed high discharge capacities, an excellent high-rate capability and an enhanced cycling performance.

Direct exfoliation of graphite to graphene by a facile chemical approach.

Facile exfoliation of graphite: High-quality graphene sheets are produced directly from graphite by a facile chemical approach. The new strategy for non-oxidized chemical exfoliation of graphite is based on a pre-intercalated process with oleum and a further strong reaction with sodium in the graphite layers under grinding conditions. This method is facile, low cost, and high throughput.

Electrocatalysis on shape-controlled titanium nitride nanocrystals for the oxygen reduction reaction.

The high price of platinum (Pt)-based cathode catalysts for the oxygen reduction reaction (ORR) have slowed down the practical application of fuel cells. Thanks to their low cost, and outstanding, stable catalytic properties, titanium nitrides (TiN) are among the most promising non-precious metal electrocatalysts for replacing Pt. However, the shape-activity relationships of TiN electrocatalysts have not been well-studied or understood up to now. In this work, by simply adjusting the shape of TiO2 precursor, we are able to tailor the morphology of the TiN catalysts from nanoparticles to nanotubes. We have synthetized uniform carbon-coated titanium nitride nanotubes (carbon-coated TiN NTs) through a nitridation reaction in NH3 flow using a TiO2 nanotubes/melamine mixture as precursor. The carbon-coated TiN NTs hybrids exhibit excellent electrocatalytic activity for the ORR, coupled with superior methanol tolerance and long-term stability in comparison to commercial Pt/C, through an efficient four-electron-dominant ORR process. Compared with nanoparticles, the one-dimensional and hollow structure of the nanotubes result in greater diffusion of electrolyte and superior electrical conductivity, and contribute to the greatly improved electrocatalytic performance of the carbon-coated TiN NTs nanocomposites.