Polyimide-derived carbon nanofiber membranes as free-standing anodes for lithium-ion batteries

Abstract

Free-standing and flexible carbon nanofiber membranes (CNMs) with a three-dimensional network structure were fabricated based on PMDA/ODA polyimide by combining electrospinning, imidization, and carbonization strategies.

N-Doped carbon nanoparticles on highly porous carbon nanofiber electrodes for sodium ion batteries

“…Moreover, it increases defects on the surface of the carbon materials, thereby enhancing the capacity. 21 Ghani et al 7 was also studied hard carbon based electrodes and reported superior capacity with high C rate performance. In N-PCNF4, high amount of nitrogen functional groups and porous fiber structure provided more active sites, enhanced electrical conductivity, and surface polarity, all led to excellent cycling performance.…”

“…[15][16][17] Polyacrylonitrile (PAN) has been commonly used as carbon precursor owing to its high carbon yield and good mechanical properties. [18][19][20][21][22] Production of high performance electrode materials via low cost and facile approach is vital to use sodium ion batteries in practical applications. 3,9,23 Morphology, porosity and pore structure, affect the electrochemical properties of carbon materials and nanober production technique inuence the porosity and pore structure.…”

Core–Shell Structured Polyimide@γ-Al2O3 Nanofiber Separators for Lithium-Ion Batteries

“…As shown in Figure 4a, all the samples have excellent mechanical properties, and the tensile strengths of the PI, PI/γ-Al 2 O 3 , and PI@γ-Al 2 O 3 nanofiber membranes are 67, 62, and 75 MPa, respectively. In general, the tensile strength of the PI nanofiber membrane has been greatly reinforced through the triple crosslinking strategy, 22 while the PI@γ-Al 2 O 3 nanofiber membrane maintains high mechanical strength, possibly due to the increasing number of crosslinking points. Furthermore, all nanofiber membranes have excellent thermal stability with an outstanding 5% weight loss temperature (T 5% ) beyond 470 °C, as shown in Figure 4b.…”

“…28 Therefore, the triple crosslinking strategies, including pre-rolling, solvent, and chemical imidization crosslinking of the PI nanofiber membrane were proposed to improve the mechanical strength of the PI nanofiber membrane in our previous study. 22 Like polyolefin materials, the wettability of PI nanofiber membranes is also poor, which means that they cannot meet the application requirements of LIBs at present. 29,30 In many studies, the electrolyte affinity of PI membranes can be further improved by combining inorganic materials.…”

“…To address the shortcomings of the polyolefin separator discussed above, a new generation of separators with excellent thermal stability are put forward. The polyimide (PI) nanofiber membrane obtained via the electrospinning process has been widely applied and highly appreciated in relevant businesses due to its outstanding thermal stability, tremendous electrolyte uptake, and ease of preparation. − However, the PI nanofiber membrane obtained via the electrospinning process is fragile because of the commonly overlapped internal fiber structure and the disordered arrangement. − In addition, the bulkiness structure of the nanofiber membrane will be damaged after long-term charge–discharge cycles . Therefore, the triple crosslinking strategies, including pre-rolling, solvent, and chemical imidization crosslinking of the PI nanofiber membrane were proposed to improve the mechanical strength of the PI nanofiber membrane in our previous study …”