No abstract

No abstract

To obtain low sheet resistance, high optical transmittance, small open spaces in conductive networks, and enhanced adhesion of flexible transparent conductive films, a carbon nanotube (CNT)/silver nanowire (AgNW)-PET hybrid film was fabricated by mechanical pressing-transfer process at room temperature. The morphology and structure were characterized by scanning electron microscope (SEM) and atomic force microscope (AFM), the optical transmittance and sheet resistance were tested by ultraviolet-visible spectroscopy (UV-vis) spectrophotometer and four-point probe technique, and the adhesion was also measured by 3M sticky tape. The results indicate that in this hybrid nanostructure, AgNWs form the main conductive networks and CNTs as assistant conductive networks are filled in the open spaces of AgNWs networks. The sheet resistance of the hybrid films can reach approximately 20.9 to 53.9 Ω/□ with the optical transmittance of approximately 84% to 91%. The second mechanical pressing step can greatly reduce the surface roughness of the hybrid film and enhance the adhesion force between CNTs, AgNWs, and PET substrate. This process is hopeful for large-scale production of high-end flexible transparent conductive films.

High energy density solid‐state lithium batteries require good ionic conductive solid electrolytes (SE) and stable matching with high‐voltage electrode materials. Here, a highly homogeneous poly(1,3‐dioxolane) composite solid electrolyte (CSE) membrane that can satisfy the above‐mentioned requirements by in situ catalytic polymerization effect of yttria stabilized zirconia (YSZ) nanoparticles on the polymerization of 1,3‐dioxolane (DOL), is reported. The well‐dispersed YSZ nanoparticle catalyst leads to the polymerization conversion of DOL monomers up to 98.5%, which enlarges its electrochemical window exceeding 4.9 V. YSZ also significantly improves the room temperature ionic conductivity (2.75 × 10−4 S cm−1) and enhances the cycle life of lithium metal anode. Based on this CSE, the Li(Ni0.6Co0.2Mn0.2)O2 (NCM622)‐based solid‐state lithium battery shows a long cycle life over 800 cycles. This investigation encourages polymer SE toward practical high energy solid‐state batteries.

Summary Three‐dimensional (3D) nitrogen‐doped carbon nanofibers (N‐CNFs) which were originating from nitrogen‐containing zeolitic imidazolate framework‐8 (ZIF‐8) were obtained by a combined electrospinning/carbonization technique. The pores uniformly distributed in N‐CNFs result in the improvement of electrical conductivity, increasing of BET surface area (142.82 m2 g−1), and high porosity. The as‐synthesized 3D free‐standing N‐CNFs membrane was applied as the current collector and binder free containing Li2S6 catholyte for lithium‐sulfur batteries. As a novel composite cathode, the free‐standing N‐CNFs/Li2S6 membrane shows more stable electrochemical behavior than the CNFs/Li2S6 membrane, exhibiting a high first‐cycle discharge specific capacity of 1175 mAh g−1at 0.1 C and keeping discharge specific capacity of 702 mAh g−1 at higher rate. More importantly, as the sulfur mass in cathodes was increased at 7.11 mg, the N‐CNFs/Li2S6 membrane delivered 467 mAh g−1after 150 cycles at 0.2 C. The excellent electrochemical properties of N‐CNFs/Li2S6 membrane can be ascribed to synergistic effects of high porosity and nitrogen‐doping in N‐CNFs from carbonized ZIF‐8, illustrating collective effects of physisorption and chemisorption for lithium polysulfides in discharge‐charge processes.

No abstract

A promising solid polymer blend electrolyte is prepared by blending of poly(ethylene oxide) (PEO) with different content of amorphous poly(propylene carbonate) (PPC), in which the amorphous property of PPC is utilized to enhance the amorphous/free phase of solid polymer electrolyte, so as to achieve the purpose of modifying PEO-based solid polymer electrolyte. It indicates that the blending of PEO with PPC can effectively reduce the crystallization and increase the ion conductivity and electrochemical stability window of solid polymer electrolyte. When the content of PPC reaches 50%, the ionic conductivity reaches the maximum, which is 2.04 × 10 −5 S cm −1 and 2.82 × 10 −4 S cm −1 at 25 C and 60 C, respectively. The electrochemical stability window increases from 4.25 to 4.9 V and the interfacial stability of lithium metal anode is also greatly improved. The solid-state LiFePO 4 //Li battery with the PEO/50%PPC blend solid polymer electrolyte has good cycling stability, which the maximum discharge specific capacity is up to 125 mAh g −1 at a charge/discharge current density of 0.5 C at 60 C.

No abstract