Design and Construction of Porous Silicon Materials as Stable Anodes for Lithium-Ion Batteries

Abstract

Silicon is considered to be the most promising anode material for the next generation of lithium-ion batteries (LIBs), but its application is limited by the severe capacity decline due to volume expansion of up to 300%. Considering the inward accumulation of the stress produced during the actual lithiation process and the stabilizing effect of oxygen element, structural design and surface oxygen content regulation work together to improve the cyclic stability of silicon. Herein, we report the design and construction of novel porous silicon materials with regulated pore structure and surface oxygen content. The facile strategy for the synthesis of the materials is using Mg 2 Si and tetraethyl orthosilicate (TEOS) as Si resource, and the oxygen in the feedstock is ingeniously used at the same time. A series of Si anode materials with different pore structure and surface oxygen content were obtained by adjusting the proportion of Mg 2 Si and TEOS. Using 0.5 g of Mg 2 Si and 1 g of TEOS to prepare the material, the electrode reaches the optimum electrochemical performance with a discharge capacity of 935.9 mAh g −1 after 100 cycles and 587.2 mAh g −1 after 300 cycles at 0.5 and 1 A g −1 , respectively. This work provides a new strategy for the design and preparation to boost stable lithium ion storage of silicon anode materials.

Scalable Synthesis of a Porous Micro Si/Si-Ti Alloy Anode for Lithium-Ion Battery from Recovery of Titanium-Blast Furnace Slag

“…As shown in Figure S8, the electrode swelling after 100 cycles at 500 mA g –1 is observed to be 198.5, 185.8, 153.8, and 173.3% for Si 1/3 TiAl 0.36 , Si 1/4 TiAl 0.36 , Si 1/4 TiAl 0.48 , and Si 1/5 TiAl 0.36 , respectively, which is consistent with the results of the electrochemical performance test. The porous structure buffers the volume expansion of Si, enabling the Si/Si-Ti anode to maintain an intact structure during the lithiation/delithiation …”

“…To address these challenges, several strategies have emerged in recent years. One approach involves nanoengineering to reduce the particle size (<150 nm) of Si anodes, thereby shortening the diffusion path of lithium ions and mitigating volume expansion. ,, Introducing carbonaceous materials into Si can create a conductive network, enhancing charge transfer capability, buffering the volume expansion, and stabilizing the SEI film, ultimately improving cyclic stability. , Advanced porous Si anodes can be achieved through methods like metallothermic reduction − or acid etching . These techniques provide a larger specific surface area and more active sites for electrochemical reactions as well as ample buffer space for volume expansion. , However, the increased specific surface area of porous Si leads to low tap density, greater electrolyte consumption, and an increase in irreversible reactions, resulting in reduced initial Coulombic efficiency (ICE) and an increased irreversible capacity .…”

Bio‐Inspired Electrodes with Rational Spatiotemporal Management for Lithium‐Ion Batteries

“…[133] Consequently, side reactions with the electrolyte occur, causing severe structural pulverization and rapid capacity fading of the electrode. [38,[134][135][136][137][138][139][140][141] Therein, the Si anode forms SEI and achieves prelithiation during the first cycle, resulting in excess lithium-ion consumption and large irreversible capacity losses. [142][143][144] The other challenge is the relatively low intrinsic electronic conductivity, which is severely affecting the rate capability.…”

Flexible Silicon/Titanium Dioxide/Reduced Graphene Oxide Self-Standing Electrode with High Performance and High Stability for Lithium-Ion Batteries

“…To mitigate the effect of volumetric expansion, nanosized Si-based materials featuring diverse morphological structures have been used, such as 0D (nanoparticles), , 1D (nanowires), 2D (thin film), and 3D (porous structure) . Carbon materials are usually introduced to solve particle crushing, − and synergistic effect has been found by combining carbon materials and metal oxides. − It is worth mentioning that titanium dioxide (TiO 2 ) is low-cost and zero-strain .…”