Silicene Flowers: A Dual Stabilized Silicon Building Block for High-Performance Lithium Battery Anodes

Abstract

Nanostructuring is a transformative way to improve the structure stability of high capacity silicon for lithium batteries. Yet, the interface instability issue remains and even propagates in the existing nanostructured silicon building blocks. Here we demonstrate an intrinsically dual stabilized silicon building block, namely silicene flowers, to simultaneously address the structure and interface stability issues. These original Si building blocks as lithium battery anodes exhibit extraordinary combined performance including high gravimetric capacity (2000 mAh g at 800 mA g), high volumetric capacity (1799 mAh cm), remarkable rate capability (950 mAh g at 8 A g), and excellent cycling stability (1100 mA h g at 2000 mA g over 600 cycles). Paired with a conventional cathode, the fabricated full cells deliver extraordinarily high specific energy and energy density (543 Wh kg and 1257 Wh L, respectively) based on the cathode and anode, which are 152% and 239% of their commercial counterparts using graphite anodes. Coupled with a simple, cost-effective, scalable synthesis approach, this silicon building block offers a horizon for the development of high-performance batteries.

Scalable 2D Mesoporous Silicon Nanosheets for High‐Performance Lithium‐Ion Battery Anode

“…To date, various 2D anode materials like titanium oxides, transition metal oxides, metal phosphides/sulfides/nitrides, have been extensively applied for LIBs. Among these 2D anode materials, 2D silicon have received intense attention as one of the most promising high‐capacity electrodes for the next‐generation LIBs due to its ultrahigh theoretical lithium storage capacity, faster Li diffusion rates, and relatively low discharge potential, as well as lower diffusion energy barrier (0.23 eV) of lithium ions . Despite these impressive benefits in 2D Si anodes, there remains a crucial challenge to realize its large‐scale preparation using low‐cost method.…”

Scallop‐Inspired Shell Engineering of Microparticles for Stable and High Volumetric Capacity Battery Anodes

“…Unless otherwise specified, the capacity values reported were calculated on the basis of the total weight of the tested electrodes. It can be observed that the mSi@OG@RGO shows similar cyclic voltammetry (CV) peaks (Figure a and Figure S6, Supporting Information) and galvanostatic voltage profiles (Figure b) to those of other silicon anodes . Figure c displays the rate performance of the mSi@OG@RGO and the mSi@RGO control sample, demonstrating high rate capability of the mSi@OG@RGO.…”

“…To address this electrode formulation failure and advance the use of silicon as the LIB anode material, various nanostructured silicon building blocks (e.g., nanoparticles, nanowires, nanotubes, and nanosheets) have been engaged, considering that structural fracture can be avoided, and electrical disconnection can be alleviated when decreasing the material feature size to the nanoscale . In particular, a wide range of materials design concepts have been further developed to construct void‐involved silicon/carbon nanostructures such as point‐to‐point contacted yolk–shell and line‐to‐line contacted wire‐in‐tube Si–C nanohybrids, so as to minimize destruction of the electrode architecture by the volume change of individual material particles as well as render a stable SEI on the surface of individual material particles thereby restraining the degradation of electron/lithium ion transport paths from/to silicon.…”

“…In particular, a wide range of materials design concepts have been further developed to construct void‐involved silicon/carbon nanostructures such as point‐to‐point contacted yolk–shell and line‐to‐line contacted wire‐in‐tube Si–C nanohybrids, so as to minimize destruction of the electrode architecture by the volume change of individual material particles as well as render a stable SEI on the surface of individual material particles thereby restraining the degradation of electron/lithium ion transport paths from/to silicon. Although being successful in extending the cycling life of silicon, the use of silicon nanostructures and their nanohybrids has inevitably incurred new fundamental challenges, some of which include increased side reactions and lowered coulombic efficiency due to higher surface area, low tap density and compromised volumetric capacity (and, therefore, energy density), weakened electrical properties and generally reduced rate capability because of excess interparticle resistances (and also intrinsically limited Si–C contact modes in the case of popular void‐involved Si–C nanohybrids), and also poor scalability and unacceptable cost due to complex synthesis processes.…”

Two‐dimensional materials of group‐IVA boosting the development of energy storage and conversion

“…Silica fume and magnesium (Mg) powder as starting materials were mixed together and then heated to a high temperature to synthesize silicene (Figure 4). 73 As‐prepared silicene flowers were further employed as lithium battery anodes, which exhibited extraordinary electrochemical performance. The feasibility of this technique endows great potential for the preparation of silicene.…”