Constructing a Yolk–Shell Structure SiO_x/C@C Composite for Long-Life Lithium-Ion Batteries

Abstract

Silicon oxide is one of the most representative anode materials for lithium-ion storage. However, the poor conductivity of silicon oxide and the large volume expansion during the repeated lithium alloying/dealloying reaction have a huge impact on the cycle stability of the electrode. Here, we propose a design strategy for constructing a yolk−shell structure to enhance the electrochemical performance of the silicon oxidebased anode. Using a silane coupling agent as the raw material, organosilicon nanoparticles are prepared by hydrolysis and a selfcondensation reaction. Combining with polydiallyldimethylammonium chloride modification and polymethyl methacrylate coating, the SiO x /C@C composite with a yolk−shell structure (YS-SiO x /C@C) was obtained by one-step carbonization. The modification of polydiallyldimethylammonium chloride ensures the formation of a stable cavity during the pyrolysis process, which can effectively relieve the volume variation of the silicon oxide electrode, and the carbon shell can enhance the overall conductivity. As the anode of lithium-ion batteries, the YS-SiO x /C@C electrode showed outstanding electrochemical stability with a high specific capacity of 770 mAh g −1 and a Coulombic efficiency of 99% after 500 cycles (0.5 A g −1 ). This research provides a direction for the preparation of yolk−shell electrode materials and promotes further development of high-performance silicon oxide-based anodes.

Para Grass-Derived Porous Carbon-Rich SiOx/C as a Stable Anode for Lithium-Ion Batteries

“…The high resolution of C 1s is fitted into C�O, C−O, and C�C peaks at 288.73, 286.23, and 284.93 eV (Figure 2d). 33,40 The deconvolution of the O 1s spectrum (Figure 2e) presents three peaks at around 536, 532.68, and 530.88 eV, corresponding to Si−O, C−O, and C�O bonds, respectively. 33 Meanwhile, the Si 2p spectrum, reconfirming the presence of Si (Figure 2f), shows two deconvolution peaks at 103.18 and 105 eV, corresponding to Si 3+ and Si 4+ .…”

Expanding the horizons of covalent organic frameworks: sub-stoichiometric synthesis as an emerging toolkit for functional COFs

“…16A). 152 Both the COFs exhibited high surface area (∼1000 m 2 g −1 ), with similar water adsorption characteristics (∼450 cm 3 g −1 at P/P o = 0.98). The stepwise water adsorption characteristics and comparably low water contact angle (78.9°) of TPE-TPB-B signies the role of dangling formyl groups in making the pores hydrophilic.…”

“…Since the rst report on sub-stoichiometric COFs, there are only three instances of polymorphism reported. 116,149,152 These reports on Type III COFs involve the use of tetratopic monomers and rhombic topologies. In these attempts, COFs with unreacted carbonyls were realized just by changing the solvent(s) rather than the stoichiometry of the monomers.…”

Boosting the Cell Performance of the SiO/Cu and SiO/PPy Anodes via In‐Situ Reduction/Oxidation Coating Strategies

“…Additional references cited within the Supporting Information. [46][47][48][49][50][51][52][53][54][55][56]…”