Introduction
Battery choice for ESS
Energy storage technologies are one of the most important issues in modern society, as global energy issues such as power outages and blackouts have caused inconveniences to billions of consumers1-3. Accordingly, most energy conversion and energy generation systems are in a combined state with several energy storage systems (ESS)6.
Anode Material choice for LIB
Therefore, Si, Ge, Sn, Sb and Al receive relatively large amounts of Li+ compared to other materials belonging to the intercalation and conversion mechanism51. Finally, the ionic self-conducting solid electrolyte interphase (SEI) layers thicken to block further diffusion of Li+ and the batteries fail55.
Potentials and progress of silicon anode
Different dimensional Si materials of 0-dimensional (0D) Si nanoparticles (SiNPs), 1D Si nanotubes or nanowires (SiNTs or SiNWs), 2D Si nanosheets (SiNS), and 3D porous Si (p-Si) have been extensively investigated in their electrochemical properties59 . General strategy of Si anodes, including electrolyte control, size control, doping, functionalization, morphology control and composite formation69.
Then, titania (TiO2) was uniformly coated on the inner and outer surface of SiO2 nanotubes by coprecipitation (ESI, Fig. S1 and S2b). Finally, we synthesized many Si-based nanotubular components composed of Si/Al2O3 and titanium silicide coating layers (Fig. 2- 1b). The final product, titanium silicide-coated Si-based multicomponents, was first confirmed by X-ray diffraction (XRD) analysis (Fig. 2-1c).
Subsequent aluminothermic reduction of the SiO2@TiO2 sample led to the formation of tubular shaped TixSiy-coated porous Si/Al2O3 (Si@TixSiy) (Fig. 2-2e). In contrast, bare and carbon-coated Si nanotubes showed poor rate performances of 4.5% and 8.3%, respectively, under the same experimental condition (EIS, Figures S8a and 8b). These results are consistent with the electrode swelling results shown in Fig. TixSiy and Al2O3 layers provided excellent structural integrity and stability on the surface of Si-based anodes.
High resolution (HR)-TEM images of SiNSs show that as-synthesized SiNSs have porous structures, which are mainly composed of mesopores (~20 nm) and some nanopores (Fig. 3-2a and 3-2b). The A-SiNS sample showed more crumbled and 2D nanosheet structure with increased thickness compared to the N-SiNS (SI, Fig. S9a). 9-nm-thick carbon layers were uniformly coated on the SiNS surface as confirmed by TEM analysis (Figs. S10a and 10b).
The cycling performance of the T-SiNS anode at a rate of 0.2 C showed serious deterioration after 60 cycles (SI, Fig. S11b). In addition, we measured cross-sectional SEM images of all SiNS electrodes after 200 cycles at 0.2 C, together with pristine electrodes (SI, Fig. S12). Due to the synergistic effect of the porous structure and uniform passivation layers, excellent cycle stability at a rate of 0.2 C in the case of ASWO electrodes was obtained against etched Al-Si electrodes (Fig. 5-4b).
Nanotubular structured Si-based multicomponent anodes for high-performance lithium-
Experimental
Results and discussion
Conclusion
Synthesis of Ultrathin Si Nanosheets from Natural Clays for Lithium-Ion Battery
Introduction
Experimental
Results and discussion
Conclusion
Multiscale Hyperporous Silicon Flake Anodes for high Initial Coulombic Efficiency
Experimental
This reactor was then placed in a tube furnace and heated to a high temperature (650 oC) for 3 hours. Then, 1 M HCl was added to this solution and further stirred at room temperature for 3 h to remove MgO byproducts. Meanwhile, for the photocatalytic measurements, the native oxide layers were additionally washed with 0.5% HF solution for 10 min.
SEM (Verios 460, FEI) was used to characterize the surface morphologies of HPSF samples at an accelerating voltage of 10 kV and current of 0.4 nA. The dimensions and internal structures of HPSF were determined using TEM (JEOL-2100) and HRTEM (JEOL-2100C) at an accelerating voltage of 200 kV. To investigate the microstructures and degrees of crystallinity of HPSF samples, XRD analyzes (D8 ADVANCE, Bruker) were performed using Cu-Kα radiation (λ = 1.5418 Å); Raman spectroscopy (alpha300R confocal microscope, WlTec) was also employed for this purpose.
Pore sizes and surface areas were characterized using a surface area and pore size analyzer (BELSORP-mini II, BEL Japan, Inc.) at 77 K for P/P0 0.05–0.3. After cycling, the cells were disassembled in the glove box and washed with dimethyl carbonate (DMC) to remove residual electrolyte and any other impurities.
Results and discussion
Moreover, the Raman spectrum of HPSF@C exhibited a disordered (D) and graphene. G) band (D/G) ratio of 2.19, indicating that the amorphous carbon layers were coated on the surface of HPSF (see SI, Figure S9e). The electrochemical performance of both HPSF and HPSF@C was evaluated using CR2016 type coin cells in the potential window from 0.01 to 1.2 V. This unusually high reversibility of HPSF is attributed to the fact that it retains its macro-sized structure with dominant macropores.
To demonstrate this aspect, we fabricated an electrode composed of HPSF and polymer binders on a hard substrate. As depicted in Figure S13a, the binders effectively covered the entire surface of the HPSF particles, and they were intertwined with the macropores of HPSF (see SI, Figures S12b–S12d). Surprisingly, the HPSF@C electrode cyclically maintained a 1C rate of 74.4% after 400 cycles, still outperforming commercial graphite anodes in terms of capacity, despite the micro-Si anode.
Furthermore, carbon layers aid in the formation of thin and uniform SEI layers over the HPSF surface. It can be attributed to SiOx surface layers and thin carbon coating layers on the HPSF@C, which can act as a good promoter to form stable SEI layers.
Conclusion
Yang, X.; Shi, C.; Zhang, L.; Liang, G.; Nine, S.; Wen, Z., Preparation of three-dimensional porous silicon by fluorine-free method and its application in lithium-ion batteries. ONE.; Maier, J.; Yu, Y., Energy storage materials from nature through nanotechnology: A sustainable route from reed plants to a silicon anode for lithium-ion batteries. H.; Ercius, P.; Rong, J.; Fang, X.; Mecklenburg, M.; Zhou, C., Large-Scale Fabrication, 3D Tomography and Lithium-Ion Battery Application of Porous Silicon.
Jia, H.; Go up.; Yang, J.; Wang, J.; Nuli, Y.; Yang, Z., Novel three-dimensional mesoporous silicon for high-power lithium-ion battery anode material. T.; Chen, J., Multilayered Si nanoparticle/reduced graphene oxide hybrid as a high-performance lithium-ion battery anode. Lin, N.; He, Y.; Wang, L.; Zhou, J.; Zhou, J.; Zhu, Y.; Qian, Y., Preparation of nanocrystalline silicon from SiCl4 at 200 oC in molten salt for high performance anodes for lithium ion batteries.
Mr.; Kim, I.-D.; Park, C.-J., Mass-scalable synthesis of 3D porous germanium-carbon composite particles as an ultra-high-rate anode for lithium-ion batteries. Zhang, Z.; Wang, Y.; Ren, W.; Tan, Q.; Chen, Y.; Li, H.; Zhong, Z.; Su, F., Scalable synthesis of interconnected porous silicon/carbon composites by Rochow reaction as high-performance lithium-ion battery anodes.
Introduction
A cost-effective approach for the structural evolution of multicomponent Si-based components for Li-ion battery anodes. However, after repeated cycles, only 700 mAh g-1 of reversible capacity was achieved at the expense of anodic capacity. In this regard, we report on silicon-based multicomponent anodes by selective etching and subsequent Al-Si alloy wet oxidation (ASWO) to achieve a novel architecture of Al2O3 passivated porous Si multicomponents exhibiting excellent electrochemical performance.
Depending on the amounts of Al remaining after the controlled etching process, a dissimilar behavior of the microstructure was obtained. The relatively Al-rich phase developed into a large part of the Al2O3 layers, leaving structural asymmetry in the core of the spheres. Instead, the Si-rich phase retained a uniform distribution of Al2O3 among the spheres, which lose their structural robustness in the absence of the nuclei.
Optimized Si-based multicomponent anodes have structural integrity arising from Al/Al2O3 core support and interfacial stability, leading to uniform SEI formation. The remarkable battery performance was evaluated in both half-cell and full-cell lithium batteries composed of lithium cobalt oxide (LCO)/natural graphite (NG)-Si multicomponent, which can show stable cycling (cycle retention of 81.9% at a rate of 0.2 °C after 500 cycles in half cells and 75.3% at a rate of 1 °C after 200 cycles in full cells), speed capability (92.5% capacity retention at 5 °C compared to 0.2 °C) and suppresses swelling problem (18.2% after 30 cycles).
Experimental
The potential windows for all cycled cells ranged from 0.005 to 1.5 V for anode half-cell and 3 to 4.3 V for cathode half-cell and full-cell versus Li/Li + . The electrolyte consisted of 1.3M LiPF6 in 3:7 v/v ethylene carbonate/diethyl carbonate with 10 wt% fluorinated ethylene carbonate additives to improve cycling stability. After cycling, each cell was opened in the glove compartment and washed with dimethyl carbonate to remove residual electrolyte and any other impurities.
Results and discussion
As a result, asymmetric distribution of Al was observed in both samples, although corresponding Al2O3 layers were formed on the outer shells (Figure 5-2i-p). There was no asymmetry in the structure and distribution of Al with solid coated layers of amorphous Al2O3 (Fig. 5-2e-h). Apparently, Al loss occurred regardless of residual Al amounts, with the ASWO-10 sample in particular showing the lowest rate of loss (Fig. S6f, ESI † ).
Interfacial instability, which resulted in the absence of Al2O3 layer, resulted in severe capacity drop and fluctuating coulombic efficiency (Fig. S8c, ESI†). Similarly, moderately formed Al2O3 layers in ASWO-10 may enhance lithium ion diffusion through Li-Al-O interlayers instead of acting as a barrier for lithium ion in the case of ASWO-20 and ASWO-40, which can be confirmed by rate capacity test varying charge rate at a fixed discharge rate of C/5 (Fig. 5-4c). For example, ASWO-04 lost its spherical structure due to the absence of core and passivation layers (Fig. S11a, ESI † ).
The full cell composed of ASWO-10/NG anode shows the most obvious electrochemical results including ICE of 91.0% in the first charge/discharge profiles (Fig. 5-6a inset) and negligible capacity reduction after 200 cycles at a rate of 1 C yielding 0.744 mAh cm-2 corresponding to a capacity retention of 75.3%. The rate capability of the full cell was also investigated by varying the discharge rates from C/10 to 5C for every 5 cycles (Fig. 5-6b).
Conclusion
Tuning the electrochemical performance of silicon-based anodes for lithium-ion batteries using atomic layer-deposited alumina coatings. Hollow carbon nanospheres/silicon/alumina core-shell as anodes for lithium-ion batteries. Ⅱ Si-based Nanotubular Structured Multicomponent Anodes for High-Performance Lithium-Ion Batteries with Controlled Pore Size viacoaxial electro-spinning---.
High-capacity anode materials for lithium-ion batteries: Selection of elements and structures for active particles. 25th Anniversary Article: Understanding Lithiation of Silicon and Other Alloy Anodes for Lithium-Ion Batteries. Nanotube-structured multicomponent Si-based anodes for high-performance lithium-ion batteries with controllable pore sizes via coaxial electrospinning.
Finally, we synthesized nanotubular Si-based multicomponents consisting of Si/Al2O3 and titanium silicide coating layers (Fig. 2-1b). Subsequent aluminothermal reduction of the SiO2@TiO2 sample led to the formation of tubular TixSiy-coated porous Si/Al2O3 (Si@TixSiy) (Fig. 2-2e). Thin silicon films as anodes for high-performance lithium-ion batteries with effective voltage relaxation.
Study of the cyclability of silicon-carbon composite anodes for lithium-ion batteries using electrochemical impedance spectroscopy.
