Enabling a high capacity and long cycle life for nano-Si anodes by building a stable solid interface with a Li⁺-conducting polymer

Abstract

Great efforts have been devoted to developing nano-Si anodes for next-generation lithium ion batteries (LIBs); however, the reversible capacity and cycling stability of all Si anodes developed so far still need to be improved for battery applications. In this work, we propose a new strategy to develop a cycling-stable Si anode by embedding nano-Si particles into a Li + -conductive polymer matrix, in which a stable Si/polymer interface is established to avoid the contact of the Si surface with the electrolyte and to buffer the volume change of the Si lattice during cycles, thus promoting the capacity utilization and long cycle life of nano-Si particles. The nano-Si/polybithiophene composite synthesized in this work demonstrates a high Li-storage capacity of >2900 mA h g À1 , a high-rate capability of 12 A g À1 and a long-term cyclability with a capacity retention of >1000 mA h g À1 over 1000 cycles, possibly serving as a high capacity anode for lithium battery applications. In addition, the fabrication technique for this type of composite material is facile, scalable and easily extendable to other Li-storable metals or alloys, opening up a new avenue for developing high capacity and cycling-stable anodes for advanced Li-ion batteries. † Electronic supplementary information (ESI) available: FTIR spectra of the Si/PBT composite, SEM images of PBT and the Si/PBT composite, charge-discharge prole and cycling performance of the coin-type full cells using the Si/PBT as the anode and NCM as the cathode, the electrochemical impedance spectra (EIS) of the Si/PBT electrode at different cycles, XPS spectra of C 1s and O 1s collected from the surface of the Si/PBT electrode at different cycles, the EIS spectra of the PBT electrode at different charge/discharge states, the relationship between Z re and u À0.5 in a low frequency region, and the diffusion coefficient of Li + ions in the PBT electrode at different charge/discharge states. See

Stabilized lithium-ion battery anode performance by calcium-bridging of two dimensional siloxene layers

“…4 Furthermore, Si-based materials having different structures and compositions have also been investi-gated as a means of preventing this structural damage. [5][6][7][8][9][10][11][12][13][14] For example, Si nanomaterials, including nanoparticles, 5,6 nanowires 7 and nanotubes, 8 have been reported to exhibit effective capacity retention, especially in the presence of an active carbon matrix. Amorphous Si also shows promise in this regard, 9,10 unlike crystalline Si, which is prone to high stresses and associated cracking.…”

Electrochemical performance of Si anode modified with carbonized gelatin binder

“…6c), the broad reduction peak between 0.5 V and 1.1 V can be assigned to the decomposition of electrolyte, which leads to the formation of SEI film [41]. The disappearance of this peak in the subsequent cycles suggests the formation of a stable SEI film on the surface of active material at the first cycle [42,43].…”

Synthetic Methodologies for Si‐Containing Li‐Storage Electrode Materials

“…[ 284 ] Subsequently, their group embedded Si nanoparticles into a Li + ‐conductive polymer matrix (polybithiophene) to avoid the contact of the Si surface with electrolyte and to buffer the volume change by ball‐milling ( Figure a). [ 285 ] The as‐prepared nano‐Si/polybithiophene electrodes exhibited a high Li‐storage capacity of about 2900 mA h g −1 and an excellent cyclability with a capacity retention of about 1000 mA h g −1 over 1000 cycles at 12 A g −1 . Komaba reported that a partially NaOH‐neutralized poly(acrylic acid) provides the moderate porous structure inside the composite electrodes when was examined as a binder for Si‐based anode electrodes, exhibiting an enhanced capacity retention (Figure 23b).…”