水系锌离子电池隔膜设计

Aqueous zinc-ion batteries(AZIBs)are attracting worldwide attention due to their multiple merits such as extreme safety,low cost,feasible assembly,and environmentally friendly enabled by water-based electrolytes.At present,AZIBs have experienced systematic advances in battery components including cathode,anode,and electrolyte,whereas research involving separators is insufficient.The separator is the crucial component of AZIBs through providing ion transport,forming contact with electrodes,serving as a container for electrolyte,and ensuring the efficient battery operation.Considering this great yet ignored significance,it is timely to present the latest advances in design strategies,the systematic classification and summary of separators.We summarize the separator optimization strategies mainly along two approaches including the modification of the frequently used glass fiber and the exploitation of new separators.The advantages and disadvantages of the two strategies are analyzed from the material types and the characteristics of different strategies.The effects and mechanisms of various materials on regulating the uniform migration and deposition of Zn2+,balancing the excessively concentrated nucleation points,inhibiting the growth of dendrites,and the occurrence of side reactions were discussed using confinement,electric field regulation,ion interaction force,desolvation,etc.Finally,potential directions for further improvement and development of AZIBs separators are proposed,aiming at providing helpful guidance for this booming field.

Silica coating onto graphene for improving thermal conductivity and electrical insulation of graphene/polydimethylsiloxane nanocomposites

Graphene possess extremely high thermal conductivity, and they have been regarded as prominent candidates to be used in thermal management of electronic devices. However, addition of graphene inevitably causes dramatic decrease in electrical insulation, which is generally unacceptable for thermal interface materials(TIMs) in real electronic industry. Developing graphene-based nanocomposites with high thermal conductivity and satisfactory electrical insulation is still a challenging issue. In this study,we developed a novel hybrid nanocomposite by incorporating silica-coated graphene nanoplatelets(Silica@GNPs) with polydimethylsiloxane(PDMS) matrix. The obtained Silica@GNP/PDMS composites showed satisfactory electrical insulation(electrical resistivity of over 10^(13)Ωcm) and high thermal conductivity of 0.497 W m-1K-1, increasing by 155% compared with that of neat PDMS, even higher than that of GNP/PDMS composites. Such high thermal conductivity and satisfactory electrical insulation is mainly attributed to the insulating silica-coating, good compatibility between components, strong interfacial bonding, uniform dispersion, and high-efficiency heat transport pathways. There is great potential for the Silica@GNP/PDMS composites to be used as high-performance TIMs in electronic industry.

Preparation of highly conductive graphene-coated glass fibers by sol-gel and dip-coating method

In order to fabricate highly-conductive glass fibers using graphene as multi-functional coatings, we reported the preparation of graphene-coated glass fibers with high electrical conductivity through solgel and dip-coating technique in a simple way. Graphene oxide (GO) was partially reduced to graphene hydrosol, and then glass fibers were dipped and coated with the reduced GO (rGO). After repeated solgel and dip-coating treatment, the glass fibers were fully covered with rGO coatings, and consequently exhibited increased hydrophobicity and high electrical conductivity. The graphene-coated fibers exhibited good electrical conductivity of 24.9 S/cm, being higher than that of other nanocarbon-coated fibers and commercial carbon fibers, which is mainly attributed to the high intrinsic electrical conductivity of rGO and full coverage of fiber surfaces. The wettability and electrical conductivity of the coated fibers strongly depended on the dip-coating times and coating thickness, which is closely associated with coverage degree and compact structure of the graphene coatings. By virtue of high conductivity and easy operation, the graphene-coated glass fibers have great potential to be used as flexible conductive wires, highly-sensitive sensors, and multi-functional fibers in many fields.

Enhanced Mechanical Properties of Multi-layer Graphene Filled Poly(vinyl chloride) Composite Films

In order to improve mechanical properties of soft poly(vinyl chloride)(PVC) films,we used commercial multi-layer graphene(MLG) with large size and high structural integrity as reinforcing fillers,and prepared MLG/PVC composite films by using conventional melt-mixing methods.Microstructures,static and dynamic mechanical properties of the MLG/PVC composite films were investigated.The results showed that a small amount of MLG loading could greatly increase the mechanical properties of the MLG/PVC composites.The tensile modulus of the 0.96 wt%MLG/PVC composites was up to 40 MPa,increasing by31.3%in comparison to the neat PVC.Such a significant mechanical reinforcement was mainly attributed to uniform dispersion of the large-size MLG,good compatibility and strong interactions among MLG and plasticizers and PVC.

Functional carbon materials addressing dendrite problems in metal batteries:surface chemistry,multi-dimensional structure engineering,and defects

Metal batteries that directly use active metals as anodes are considered as one of the most promising solutions to achieve the energy upgrade of battery technologies,while their practical application still suffers from dendrite problems.Functional carbon materials(FCMs)have demonstrated their great potential in suppressing metal dendrites benefitting from the multiple merits such as chemical tunability and capability of multi-dimensional structure assembly.Here,we initiate a review to present the recent progress in employing FCMs to deal with dendrite problems.It focuses on the surface chemistry and multi-dimensional carbon material engineering,which systematically overcomes the problems through diverse methods,such as reinforcing desolvation,improving interface compatibility,homogenizing electric field,buffering volume expansion and lattice mismatch.In addition,we also refine the long-standing debate about whether surface defects in FCMs are beneficial to suppress the metal dendrites or not,especially in the non-aqueous electrolyte regime.Finally,the remaining challenges for utilizing FCMs to suppress metal dendrites and the possible solutions are proposed to guide the future development.

A graphene-laminated electrode with high glucose oxidase loading for highly-sensitive glucose detection

Graphene oxide(GO) has received considerable attention for glucose detection because of high surface area, abundant functional groups, and good biocompatibility. Defects and functional groups of the GO are beneficial to immobilization of glucose oxidase(GOD), but sacrificing electron-transfer capability for highly-sensitive detection. In order to obtain high GOD loading and highly-sensitive detection of biosensors, we first designed and fabricated a graphene-laminated electrode by combining GO and edgefunctionalized graphene(FG) layers together onto glassy-carbon electrode. The graphene-laminated electrodes exhibited faster electron transfer rate, higher GOD loading of 3.80 × 10^(-9) mol·cm^(-2), and higher detection sensitivity of 46.71 μA·mM^(-1)·cm^(-2) than other graphene-based biosensors reported in literature. Such high performance is mainly attributed to the abundant functional groups of GO, high electrical conductivity of FG, and strong interactions between components in the graphene-laminated electrodes.By virtue of their high enzyme loading and highly-sensitive detection, the graphene-laminated electrodes show great potential to be widely used as high-performance biosensors in the field of medical diagnosis.

Transfer-free CVD graphene for highly sensitive glucose sensors

Chemical vapor deposition(CVD)graphene film is a promising electrode-modifying material for fabricating high-performance glucose sensor due to its high electrical conductivity and two-dimensional structure over large area.However,the use of typical metal-based CVD graphene suffers from the residue contamination of polymer transfer-support and heavy metal ions.In this work,we directly grew fewlayer graphene on the SiO2/Si substrate without transfer process and then fabricated graphene-based glucose sensors by sequentially immobilizing glucose oxidase and depositing Nafion layer on its surface that was functionalized by oxygen-plasma treatment.Our transfer-and metal-free process shows distinct advantage over the common metal-CVD method in improving the electrochemical performance by eliminating the contamination of transfer-residue.Thus-obtained glucose sensor shows a high sensitivity(16.16μA mM-1cm-2)with a detection limit of 124.19μM.This method is simple and promising for the development of highly sensitive glucose sensors.