As a cathode for sodium‐ion batteries (SIBs), Na3V2(PO4)2F3 (NVPF) with 3D open framework is a promising candidate due to its high working voltage and large theoretical capacity. However, the severe ...capacity degradation and poor rate capability hinder its practical applications. The present study demonstrated the optimization of Na‐storage performance of NVPF via delicate lattice modulation. Aliovalent substitution of V3+ at Na+ in NVPF induces the generation of electronic defects and expansion of Na+‐migration channels, resulting in the enhancement in electronic conductivity and acceleration of Na+‐migration kinetics. It is disclosed that the formed stronger NaO bonds with high ionicity than VO bonds lead to the significant increase in structural stability and ionicity in the Na+‐substituted NVPF (NVPF‐Nax). The aforementioned effects of Na+ substitution achieve the unprecedented electrochemical performance in the optimized Na3.14V1.93Na0.07(PO4)2F3 (NVPF‐Na0.07). As a result, NVPF‐Na0.07 delivers a high‐rate capability (77.5 mAh g−1 at 20 C) and ultralong cycle life (only 0.027% capacity decay per cycle over 1000 cycles at 10 C). Sodium‐ion full cells are designed using NVPF‐Na0.07 as cathode and Se@reduced graphene oxide as anode. The full cells exhibit excellent wide‐temperature electrochemical performance from −25 to 25°C with an outstanding rate capability (96.3 mAh g−1 at 20 C). Furthermore, it delivered an excellent cycling performance over 300 cycles with a capacity retention exceeding 90% at 0.5 C under different temperatures. This study demonstrates a feasible strategy for the development of advanced cathode materials with excellent electrochemical properties to achieve high‐efficiency energy storage.
An advanced Na3.14V1.93Na0.07(PO4)2F3 cathode with high ionicity and excellent energy‐storage performance is prepared via aliovalent substitution of V3+ at Na+ sites. It exhibits the higher structural stability and improved electron/ion‐transport kinetics than the pristine Na3V2(PO4)2F3 owing to the stronger NaO and VO bonds, thereby extending the cycle life of NASICON cathode materials.
Flexible power sources featuring high-performance, prominent flexibility and raised safety have received mounting attention in the area of wearable electronic devices. However, many great challenges ...remain to be overcome, notably the design and fabrication of flexible electrodes with excellent electrochemical performance and matching them with safe and reliable electrolytes. Herein, a facile approach for preparing flexible electrodes, which employs carbon cloth derived from commercial cotton cloth as the substrate of cathode and a flexible anode, is proposed and investigated. The promising cathode (NVPOF@FCC) with high conductivity and outstanding flexibility is prepared by efficiently coating Na
3
V
2
(PO
4
)
2
O
2
F (NVPOF) on flexible carbon cloth (FCC), which exhibits remarkable electrochemical performance and the significantly improved reaction kinetics. More importantly, a novel flexible quasi-solid-state sodium-ion full battery (QSFB) is feasibly assembled by sandwiching a P(VDF-HFP)-NaClO
4
gel-polymer electrolyte film between the advanced NVPOF@FCC cathode and FCC anode. And the QSFBs are further evaluated in flexible pouch cells, which not only demonstrates excellent energy-storage performance in aspect of great cycling stability and high-rate capability, but also impressive flexibility and safety. This work offers a feasible and effective strategy for the design of flexible electrodes, paving the way for the progression of practical and sustainable flexible batteries.
Cytokine storm is a phenomenon characterized by strong elevated circulating cytokines that most often occur after an overreactive immune system is activated by an acute systemic infection. A variety ...of cells participate in cytokine storm induction and progression, with profiles of cytokines released during cytokine storm varying from disease to disease. This review focuses on pathophysiological mechanisms underlying cytokine storm induction and progression induced by pathogenic invasive infectious diseases. Strategies for targeted treatment of various types of infection-induced cytokine storms are described from both host and pathogen perspectives. In summary, current studies indicate that cytokine storm-targeted therapies can effectively alleviate tissue damage while promoting the clearance of invading pathogens. Based on this premise, "multi-omics" immune system profiling should facilitate the development of more effective therapeutic strategies to alleviate cytokine storms caused by various diseases.
Relative to electron donors for bulk heterojunction organic solar cells (OSCs), electron acceptors that absorb strongly in the visible and even near‐infrared region are less well developed, which ...hinders the further development of OSCs. Fullerenes as traditional electron acceptors have relatively weak visible absorption and limited electronic tunability, which constrains the optical and electronic properties required of the donor. Here, high‐performance fullerene‐free OSCs based on a combination of a medium‐bandgap polymer donor (FTAZ) and a narrow‐bandgap nonfullerene acceptor (IDIC), which exhibit complementary absorption, matched energy levels, and blend with pure phases on the exciton diffusion length scale, are reported. The single‐junction OSCs based on the FTAZ:IDIC blend exhibit power conversion efficiencies up to 12.5% with a certified value of 12.14%. Transient absorption spectroscopy reveals that exciting either the donor or the acceptor component efficiently generates mobile charges, which do not suffer from recombination to triplet states. Balancing photocurrent generation between the donor and nonfullerene acceptor removes undesirable constraints on the donor imposed by fullerene derivatives, opening a new avenue toward even higher efficiency for OSCs.
High‐performance fullerene‐free single‐junction organic solar cells with power conversion efficiencies up to 12.5% are reported. Transient absorption spectroscopy reveals that exciting either the donor or acceptor component efficiently generates mobile charges, which do not suffer from recombination to triplet states.
A robust superhydrophobic brass mesh was fabricated based on a low-energy surface and a roughness on the nano/micro-meter scale. It was carried out by the forming of hydroxyapatite (HP) coatings on ...its surface through a constant current electro-deposition process, followed by immersion in fluoroalkylsilane solution. Surface morphology, composition and wetting behavior were investigated by field-emission scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high speed camera, and contact angle goniometer. Under optimal conditions, the resulting brass mesh exhibited superhydrophobicity, excellent anti-corrosion (η = 91.2%), and anti-scaling properties. While the surfactant liquid droplets of tetradecyl trimethyl ammonium bromide (TTAB) with different concentration were dropped on the superhydrophobic surface, maximum droplet rebounding heights and different contact angles (CAs) were observed and measured from side-view imaging. The plots of surfactant-concentration−maximum bounding height/CA were constructed to determine its critical-micelle-concentration (CMC) value. Close CMC results of 1.91 and 2.32 mM based on the determination of maximum rebounding height and CAs were obtained. Compared with its theoretical value of 2.1 mM, the relative errors are 9% and 10%, respectively. This indicated that the novel application based on the maximum rebounding height could be an alternative approach for the CMC determination of other surfactants.
Solid‐state sodium batteries (SSSBs) are considered as promising candidates for next‐generation energy storage applications due to the probability to achieve safer and higher energy density ...characteristics. However, though SSSBs can avoid using combustible organic liquid electrolytes, the development of such novel batteries is hindered by some critical challenges. Particularly, comprehensive understandings of interfacial stability between solid‐state electrolyte and two electrodes is still absent and thus there is a long way to go for practical applications of SSSBs. In this regard, this review focuses on the grand challenges, fundamental mechanisms, and viable design strategies associated with the interfaces in SSSBs. First, the differences between liquid‐ and solid‐state batteries are compared, and the challenges remaining to be conquered are pointed out. Second, a variety of interfaces, such as interphase formation, interface between electrode and electrolyte, as well as interface of interparticle, are discussed in detail to guide the engineering of the interfaces. Following the obtained insights, systematic perspectives are listed at last to form a basis for further development of advanced SSSBs.
Solid‐state sodium batteries (SSSBs) are considered as promising candidates for state‐of‐the‐art energy‐storage technologies due to the potential benefits in safety and energy density. In this review, a comprehensive overview of the challenges associated with the interfaces in SSSBs is presented, and systematic perspectives are listed at last to form a basis for further development of such batteries.
Supported gold nanoparticles are emerging catalysts for heterogeneous catalytic reactions, including selective hydrogenation. The traditionally used supports such as silica do not favor the ...heterolytic dissociation of hydrogen on the surface of gold, thus limiting its hydrogenation activity. Here we use gold catalyst particles partially embedded in the pore walls of mesoporous carbon with carbon atoms occupying interstitial sites in the gold lattice. This catalyst allows improved electron transfer from carbon to gold and, when used for the chemoselective hydrogenation of 3-nitrostyrene, gives a three times higher turn-over frequency (TOF) than that for the well-established Au/TiO
system. The d electron gain of Au is linearly related to the activation entropy and TOF. The catalyst is stable, and can be recycled ten times with negligible loss of both reaction rate and overall conversion. This strategy paves the way for optimizing noble metal catalysts to give an enhanced hydrogenation catalytic performance.
Abstract
Oxidation of renewable polyol/sugar into formic acid using molecular O
2
over heterogeneous catalysts is still challenging due to the insufficient activation of both O
2
and organic ...substrates on coordination-saturated metal oxides. In this study, we develop a defective MnO
2
catalyst through a coordination number reduction strategy to enhance the aerobic oxidation of various polyols/sugars to formic acid. Compared to common MnO
2
, the tri-coordinated Mn in the defective MnO
2
catalyst displays the electronic reconstruction of surface oxygen charge state and rich surface oxygen vacancies. These oxygen vacancies create more Mn
δ+
Lewis acid site together with nearby oxygen as Lewis base sites. This combined structure behaves much like Frustrated Lewis pairs, serving to facilitate the activation of O
2
, as well as C–C and C–H bonds. As a result, the defective MnO
2
catalyst shows high catalytic activity (turnover frequency: 113.5 h
−1
) and formic acid yield (>80%) comparable to noble metal catalysts for glycerol oxidation. The catalytic system is further extended to the oxidation of other polyols/sugars to formic acid with excellent catalytic performance.
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With the increasing popularity of new energy electric vehicles, the demand for lithium-ion batteries (LIBs) has been growing rapidly, which will produce a large number of spent LIBs. ...Therefore, recycling of spent LIBs has become an urgent task to be solved, otherwise it will inevitably lead to serious environmental pollution. Herein, a unique recycling strategy is proposed to achieve the concurrent reuse of cathode and anode in the spent graphite/LiFePO4 batteries. Along with such recycling process, a unique cathode composed of recycled LFP/graphite (RLFPG) with cation/anion-co-storage ability is designed for new-type dual-ion battery (DIB). As a result, the recycle-derived DIB of Li/RLFPG is established with good electrochemical performance, such as an initial discharge capacity of 117.4 mA h g−1 at 25 mA g−1 and 78% capacity retention after 1000 cycles at 100 mA g−1. The working mechanism of Li/RLFPG DIB is also revealed via in situ X-ray diffraction and electrode kinetics studies. This work not only presents a far-reaching significance for large-scale recycling of spent LIBs in the future, but also proposed a sustainable and economical method to design new-type secondary batteries as recycling of spent LIBs.
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