Encapsulating Nanoscale Silicon inside Carbon Fiber as Flexible Self-Supporting Anode Material for Lithium-Ion Battery

Abstract

At present, the main limitations for the practical application of silicon (Si) as an anode material of a lithium-ion battery are huge volume variation and low electrical conductivity. Core–shell silicon/carbon (Si/C) composites can greatly relieve the Si large volume change and accelerate the low Li+ conductivity; however, cracking of carbon shell and the failure of the electrode structure still limit the lithium storage capability and cyclic life. Herein, a flexible freestanding N-doped core–shell Si/C nanofiber (SC-NF) anode is prepared by the double-nozzle electrospinning technique. It has been found that in such fibers, Si particles are encapsulated by the carbon shell of fibers, which can settle the shortcomings of pulverization and volume variation of Si. Furthermore, the highly conductive N–C shell derived from carbonized PAN can accelerate the diffusion of Li+ and charge transport. As a result, the as-prepared core–shell SC-NF-0.24 electrode exhibits an initial specific discharge capacity of 1441 mAh g–1 with a high capacity retention of 76.9% at 0.5 A g–1, and the capacity decay rate of per cycle is only 0.1% (starting on the third cycle), showing a good cycle property. Therefore, the as-prepared freestanding core–shell SC-NF material is a prospective anode material for high-performance lithium-ion batteries.

Silicon micron cages derived from a halloysite nanotube precursor and aluminum sacrificial template in molten AlCl3 as an anode for lithium-ion batteries

“…Besides, while the current density returns to 0.1 A g À1 , the reversible capacity of SMCs can immediately recover to 1881.8 mA h g À1 , suggesting excellent rate capability. A discharge specic capacity of 1035.1 mA h g À1 aer 300 cycles for SMCs electrode at a higher current density of 1.0 A g À1 was attained, which is higher than the values from the most recent reports [6][7][8][9]11,15,[22][23][24] (for detailed data, see Table S1 †). Compared with the third cycle, the capacity retention of the 300th cycle is 46.4%.…”

Thiophilic–Lithiophilic Hierarchically Porous Membrane-Enabled Full Lithium–Sulfur Battery with a Low N/P Ratio

“…Li et al showed that after the carbonization of polyacrylonitrile (PAN), it was doped with nitrogen atoms and exhibited excellent chemisorption for Li + . Experiments verified that the initial specific discharge capacity of the battery was 1441 mAh g –1 , the capacity retention rate at 0.5 C was 76.9%, and the capacity decay rate per cycle was only 0.1% . Our group prepared a N-doped hierarchically porous membrane electrode with CNTs and PAN that was used as a diaphragm to assemble lithium-ion batteries.…”

“…Experiments verified that the initial specific discharge capacity of the battery was 1441 mAh g −1 , the capacity retention rate at 0.5 C was 76.9%, and the capacity decay rate per cycle was only 0.1%. 21 Our group prepared a Ndoped hierarchically porous membrane electrode with CNTs and PAN that was used as a diaphragm to assemble lithium-ion batteries. In our previous work, the application of the membrane electrode, without any modification, as an interlayer on the lithium sheet played a role in redistributing the Li + flux and inducing uniform deposition on the Li plate, thus inhibiting the growth of lithium dendrites.…”

Black glasses grafted micron silicon: a resilient anode material for high-performance lithium-ion batteries

“…), which are electrochemically silent and become a liability in the form of additional unwanted weight, resulting in much reduced overall specic capacity. [41][42][43][44][45] These silicon oxycarbide (SiC x O 4Àx ) black glasses (BG) consist of mixed structural units of SiC 4 , SiC 3 O, SiC 2 O 2 , SiCO 3 , and SiO 4 arranged in amorphous fashion. 36,39,40 In addition, the inherent free carbon domain can also be present in this amorphous network.…”