Search

MXene-based structural materials with high mechanical robustness and excellent electrical conductivity are highly desirable for multifunctional applications. The incorporation of macromolecular polymers has been verified to be beneficial to alleviate the mechanical brittleness of pristine MXene films. However, the intercalation of a large amount of insulating macromolecules inevitably compromises their electrical conductivity. Inspired by wood, short-chained hemicellulose (xylo-oligosaccharide) acts as a molecular binder to bind adjacent MXene nanosheets together; this work shows that this can significantly enhance the mechanical properties without introducing a large number of insulating phases. As a result, MXene-hemicellulose films can integrate a high electrical conductivity (64,300 S m

Lithium-sulfur (Li-S) batteries hold great promise for new-generation energy storage technologies owing to their overwhelming energy density. However, the poor conductivity of active sulfur and the shuttle effect limit their widespread use. Herein, a carbon cloth decorated with thiol-containing UiO-66 nanoparticles (CC@UiO-66(SH)

The severe shuttle effect and sluggish reaction kinetics have hindered the commercial application of high-energy lithium-sulfur (Li-S) batteries. In this work, a dual-thiol metal-organic framework (MOF) was in situ synthesized on carbon nanotubes, and sulfur was covalently connected to this composite (UiO-66(SH)2@CNT) to form a MOF-sulfur copolymer (S-UiO-66(SH)2@CNT). Benefiting from the strong covalent interaction between thiol groups and sulfur species, the S-UiO-66(SH)2@CNT cathode can retard the shuttle effect and simultaneously strengthen the redox kinetics of polysulfides. As a result, a discharge capacity of 791 mAh g-1 is achieved at a current density of 0.2 C, whereas the S/UiO-66@CNT cathode using the blend of UiO-66@CNT and sulfur as active materials only shows a specific capacity of 670 mAh g-1. Moreover, the S-UiO-66(SH)2@CNT cathode exhibits a higher capacity retention of 93.27 % at 0.5 C during 200 cycles compared with that of the S/UiO-66@CNT cathode (64.94 %). This work will provide significant inspiration for the design of advanced MOFs and cathodes for excellent Li-S batteries.

Routine electrolyte additives are not effective enough for uniform zinc (Zn) deposition, because they are hard to proactively guide atomic-level Zn deposition. Here, based on underpotential deposition (UPD), we propose an "escort effect" of electrolyte additives for uniform Zn deposition at the atomic level. With nickel ion (Ni2+ ) additives, we found that metallic Ni deposits preferentially and triggers the UPD of Zn on Ni. This facilitates firm nucleation and uniform growth of Zn while suppressing side reactions. Besides, Ni dissolves back into the electrolyte after Zn stripping with no influence on interfacial charge transfer resistance. Consequently, the optimized cell operates for over 900 h at 1 mA cm-2 (more than 4 times longer than the blank one). Moreover, the universality of "escort effect" is identified by using Cr3+ and Co2+ additives. This work would inspire a wide range of atomic-level principles by controlling interfacial electrochemistry for various metal batteries.

Desulfurization efficiency of bis-imidazole-based ionic liquids with different alkyl chain lengths.

A hydrated deep eutectic electrolyte with a water-deficient solvation structure and reduced free water in bulk solution is proposed, resulting in highly reversible and stable Zn anodes.

Aqueous zinc-ion batteries have drawn increasing attention due to the intrinsic safety, cost-effectiveness and high energy density. However, parasitic reactions and non-uniform dendrite growth on the Zn anode side impede their application. Herein, a multifunctional additive, ammonium dihydrogen phosphate (NHP), is introduced to regulate uniform zinc deposition and to suppress side reactions. The results show that the NH

There is an urgent need to find green and efficient technologies for the sustainable reuse of the Chinese medicine residues due to their abundant annual production companied with serious environment problems. Herein, we synthesized a three-dimensional hierarchically porous carbon from Ganoderma lucidum residues for the application of supercapacitor electrodes via a molten alkali treatment activation/carbonization process. The resulting porous carbon samples had large surface areas (1347.7 m2 g−1), a hierarchical pore structure, and excellent capacitance and were obtained using much less corrosive activator compared with other studies. When used for supercapacitor, the Ganoderma lucidum residues–derived porous carbon electrode presented outstanding electrochemical performance, with specific capacitances of up to 365.6 F g−1 at 1 A g−1, and cycling stability of up to 99% after 10,000 cycles at a current density of 2 A g−1. This work broadens the application of Chinese medicine residues in the field of energy storage and provides a new avenue for high value conversion of waste resources. Using Chinese Medicine Residues as precursor, a convenient activation/carbonization process is proposed to synthesize porous carbon as supercapacitor electrode materials.

High-voltage cathodes with high power and stable cyclability are needed for future high-performance sodium-ion batteries. However, the low electronic conductivity and poor capacity retention impede the development of Mn-rich phosphate cathodes. Here, a light-weight F doping strategy is reported to modify high-voltage Na4MnCr(PO4)3 cathodes. The light-weight F dopant could decrease the energy gap to 0.22 eV from 1.52 eV and strengthen the adjacent chemical bonding around Mn as confirmed by density functional theory calculations, which ensure the boosted electronic conductivity and suppress Mn dissolution. The combination of in-situ and ex-situ techniques determine that the F dopant has no influence on the Na+ storage mechanisms. As a result, an outstanding rate performance up to 40 C and an improved cycling stability (1000 cycles at 20 C) are thus achieved (best reported performances until now). This work presents an unusual and widely available light-weight anion doping strategy for high-performance polyanionic cathodes.

Aqueous zinc-ion batteries (AZIBs) are promising for large-scale energy storage, but their development is plagued by inadequate cycle life. Here, for the first time, we reveal an unusual phenomenon of cathodic underpotential deposition (UPD) of Zn, which is highly irreversible and considered the origin of the inferior cycling stability of AZIBs. Combining experimental and theoretical simulation approaches, we propose that the UPD process agrees with a two-dimensional nucleation and growth model, following a thermodynamically feasible mechanism. Furthermore, the universality of Zn UPD is identified in systems, including VO

Wearable energy storage devices are crucial for the development of flexible and wearable electronics. However, their performance is still limited due to the addition of inactive additives and low porosity of electrodes. Herein, a novel strategy is reported to enhance the performance of flexible supercapacitor by a multifunctional interface design on cellulose substrate. The multifunctional interface can simultaneously take the function of binder, conductive additive and active material through the transition from the adhesive polydopamine interface to the nitrogen-doped carbon interface, and allows the electrode maintain nanoscale porosity and high specific area of 347.6 m2 g−1. The composite electrodes exhibit high specific areal capacitance of 3100 mF cm−2. All-solid-state supercapacitor based on them shows remarkable capacitance of 1208.4 mF cm−2 with excellent flexibility and rate capability, which is much higher than recently reported textile-based supercapacitors. This work may open up new opportunities for flexible electrodes and wearable supercapacitors with excellent performance.

For practical energy storage devices, a bottleneck is to retain decent integrated performances while increasing the mass loading of active materials to the commercial level, which highlights an urgent need for novel electrode structure design strategies. Here, an active nitrogen-doped carbon interface with "high conductivity, high porosity, and high electrolyte affinity" on a flexible cellulose electrode surface is engineered to accommodate 1D active materials. The high conductivity of interface favors fast electron transport, while its high porosity and high electrolyte affinity properties benefit ion migration. As a result, the flexible anode accommodated by carbon nanotubes achieves an ultrahigh capacitance of 9501 mF cm

Transparent, flexible, and eco-friendly touch sensors are important components for next-generation green electronics such as wearable sensors and e-skins. However, most current touch sensors, which are based on plastics or glass substrates and indium tin oxide or metal microelectrodes, are not environmentally friendly, as well as being difficult to recycle and expensive. Here, we demonstrate that a green, transparent, flexible, and recyclable nanopaper-based touch sensor (NPTS) can be fabricated via inkjet printing a conductive polymer, poly(3,4-ethylene dioxythiophene)-doped polystyrene sulfonate (PEDOT:PSS), on cellulose nanofibril paper. The materials cost of a single-keypad NPTS with a size of 3.5 cm × 2.5 cm × 0.05 mm is only $0.060. Good printability, excellent transparency (80% at 400 nm), and high conductivity (1360 S cm−1) were achieved with the PEDOT:PSS microelectrodes when using a newly developed, eco-friendly water-based ink formulation. It takes only 3–4 weeks for the NPTS to degrade completely in natural soil. A four-keypad NPTS was demonstrated by interfacing with the Arduino UNO development board. Folding, bending, and multiple finger-touch trials caused only slight capacitive changes to the NPTS, with no loss of function. The facile fabrication of the NPTS will be invaluable for many practical applications where eco-friendly, transparent, flexible, durable, recyclable, and economical touch-control is required.

Mounting studies have revealed that long non-coding RNA (lncRNA) deleted in lymphocytic leukemia 1 (DLEU1) positively regulated the initiation and development of various human malignant tumors. Nevertheless, the function and mechanism of DLEU1 in human glioblastoma multiforme (GBM) remain elusive and ill-defined. The current study was designed to highlight the functional role and disclose the underlying molecular mechanism by which DLEU1 regulated GBM development. We found that DLEU1 was up-regulated in GBM and DLEU1 knockdown significantly inhibited GBM cell proliferation and induced apoptosis. As predicted by bioinformatics analysis and validated in mechanistic assays, SP1 could bind to the promoter region of DLEU1 to activate DLEU1 transcription. Additionally, miR-4429 was verified as a target gene of DLEU1 and negatively modulated by DLEU1. More importantly, miR-4429 overexpression repressed the mRNA and protein levels of SP1 via binding to the 3′UTR of SP1. Overexpression of SP1 or miR-4429 inhibitor could partly abolish the effect of DLEU1 knockdown on cell viability and apoptosis in GBM. Accordingly, our experimental data revealed that SP1–DLEU1–miR-4429 formed a feedback loop to promote GBM development, providing a new evidence for the role of DLEU1 in GBM.

Reasonable design of hybrid graphene aerogels with low cost, high specific surface area (SSA), and excellent mechanical properties is of great significance for future large-scale energy storage applications. Herein, we report a composite aerogel of biomass carbon/reduced graphene oxide (rGO)/nanocellulose (CNF) by a one-step self-assembly method. In the hybrid aerogel, biomass carbon particles with low cost and high SSA are assembled into the framework of rGO effectively preventing the restacking of rGO nanosheets and resulting in high SSA and high conductivity. Negatively charged nanocellulose fibers act as the binder between biomass carbon particles and rGO sheets, facilitating the formation of a strengthening network. As a result, the hybrid aerogel with a high content of biomass carbon (76% mass ratio) demonstrates excellent mechanical strength (240 kPa), high SSA (1007.9 m2 g−1), and efficient MnO2 deposition capability (33.9 mg cm−2). Employing the composite aerogel as electrodes to fabricate a self-supporting supercapacitor, an admirable capacitive performance (4.8F cm−2) was achieved. This work provides an effective method to fabricate low cost hybrid graphene aerogel materials with excellent performances for wide applications.

A generalization of the Chinese Remainder Theorem (CRT) combining method is proposed to design much more and better quasi-cyclic (QC) LDPC codes when the parity check matrices of the component codes are given. It can design a much larger class of QC-LDPC codes with similar performance by loosening the condition for determining the intermediate parameters. By permuting the block rows of the parity check matrices of the component codes, a lot of QC-LDPC codes with much less 6-cycles and better performance can be designed. At a BER of 10-6 some QC-LDPC codes designed by the generalized combining method outperform those designed by the CRT combining method by 0.5 dB.

This correspondence presents an approach to the representation of cycles of Tanner graphs on associated parity-check matrices. Several equivalent conditions for the girth of a Tanner graph to be 2k are proposed. An algorithm to determine girth of associated Tanner graphs of parity-check matrices is proposed, also with an algorithm to count shortest cycles.

A new public key encryption scheme is proposed and analyzed, which is based on a vector space over some finite field with respect to a class of matrix semigroup action. The scheme is proved secure against adaptive chosen ciphertext attack under EDDH assumption. Since EDDH assumption is weaker than DDH assumption for generic bilinear groups, the new encryption scheme is a good replacement for Cramer-Shoup encryption scheme when bilinear group is adopted as construction platform.

A modified on-demand belief propagation (BP) algorithm is proposed for decoding of low-density parity-check convolutional codes. The modification improves the efficiency of the on-demand BP algorithm updating the variable information by applying the feedback information at each iteration. A BER performance better than that of the on-demand BP algorithm can be achieved, while the decoding latency is effectively reduced.