Silicon nanoparticles embedded in a porous carbon matrix as a high-performance anode for lithium-ion batteries

Abstract

Silicon-based anodes have recently received increased attentions due to their high theoretical capacity. However, the Sibased anodes always suffer large volume change during cycling and require expensive and multistep processes to prepare nano-sized Si. In this work, Si nanoparticles are successfully embedded in carbon matrix by using NaCl particles as a hard template, which were prepared through magnesiothermic reduction of SiO2 nanoparticles. Besides, NaCl particles also play an important role in absorbing the local heat accumulation generated from magnesiothermic reduction, thus preventing the agglomeration of Si particles and the formation of undesirable SiC. The as-prepared Si@PCM could not only provide fast electrons diffusion through carbon network, but also accommodate the stress-strain caused by volume change. As a result, the Si@PCM composite demonstrates an excellent electrochemical performance as an anode material for lithiumion batteries.

Facile preparation of core-shell Si@Li4Ti5O12 nanocomposite as large-capacity lithium-ion battery anode

“…Various Si nanostructures including nanotubes [12] , nanoparticles [13] , nanowires [14] , and porous nanofilms [15] , have been developed to promote the stability of materials. The surface coating, such as Si/C [16][17][18][19] , Si/CNT [12,20] , Si/graphene [16,21,22] , Si/TiO 2 [4,5,23,24] and Si/SnO 2 [25] , is considered to be another effective method to improve the electrochemical performance of Si. The composite materials prepared by these approaches protect the Si from directly contacting with the electrolyte and then reduce the uncontrollable growth of SEI layer.…”

Double Core–Shell Si@C@SiO2 for Anode Material of Lithium‐Ion Batteries with Excellent Cycling Stability

“…[7][8][9][10][11] The greati nterest currently is the pursuit of electrode materials with high theoreticalc apacity to replace the currentg raphite anode, the theoretical capacity of which is only 372 mAh g À1 .A mongt he anode materials studied,s ilicon (Si)h as been identified as ap romising candidate with ah igh theoretical capacity ( % 3579 mAh g À1 )a nd low discharge potential( < 0.5 Vv s. Li + /Li). [12] However,t he large volumev ariance( % 300 %) of Si during the charge/dischargep rocess leads to severe structural deterioration and subsequently unsatisfiedc ycle performance. Furthermore, the intrinsic low electrical conductivity of Si leads to undesirable rate performance.…”

Rationally Designed Silicon Nanostructures as Anode Material for Lithium‐Ion Batteries

“…Due to the unique three-dimensional (3D) formation, various carbon skeletons, like porous frame, [10,28] carbon bracket, [42] biomass-derived carbon [62][63][64] are extensively adopted in previous researches. As shown in Figure 4, Gueon et al presented a Si nanoparticle-nested construction, where Si nanoparticles confined and uniformly dispersed in an inverse opal carbon (IOC) through a simple mixing.…”

“…The carbon matrix can (i) accommodate the volume variation of Si nanoparticles upon charge/discharge procedures; (ii) improve the electronic conductivity of the whole composite; (iii) allow efficient transport of Li ions and electrons among the electrode and electrolyte; and (iv) low cost and convenient manufacture. Multifarious carbon materials with different configuration have been employed to synthesis Si-carbon composite, such as carbon frameworks, [42,52] porous carbon substrates, [10,28,[53][54][55][56][57][58] carbon nanotubes. [59,60] Recently, Xu et al proposed a watermelon-inspired Si/carbon (Si/C) microspheres with ingenious hierarchical buffer structure through a combination of spray drying and CVD method.…”

“…3500 mAh g À1 ), [26] which is 10 times over that of commercial graphite material, leading to high energy density and of batteries. [27,28] Additionally, the Si-based anodes also show a relatively low voltage hysteresis between the charge and discharge curves, resulting in a high energy efficiency. [29] The discharge potential of Si is approximately 370 mV (vs. Li/Li þ ), lower than that of the majority alloy-type anodes, making it suitable for full cell applications when matched with cathode materials, such as LiCoO 2 or LiMn 2 O 4 .…”