Porous Si‐Cu₃Si‐Cu Microsphere@C Core–Shell Composites with Enhanced Electrochemical Lithium Storage

Abstract

Low‐cost Si‐based anode materials with excellent electrochemical lithium storage present attractive prospects for lithium‐ion batteries (LIBs). Herein, porous Si‐Cu3Si‐Cu microsphere@C composites are designed and prepared by means of an etching/electroless deposition and subsequent carbon coating. The composites show a core–shell structure, with a porous Si/Cu microsphere core surrounded by the N‐doped carbon shell. The Cu and Cu3Si nanoparticles are embedded inside porous silicon microspheres, forming the porous Si/Cu microsphere core. The microstructure and lithium storage performance of porous Si‐Cu3Si‐Cu microsphere@C composites can be effectively tuned by changing electroless deposition time. The Si‐Cu3Si‐Cu microsphere@C composite prepared with 12 min electroless deposition delivers a reversible capacity of 627 mAh g−1 after 200 cycles at 2 A g−1, showing an enhanced lithium storage ability. The superior lithium storage performance of the Si‐Cu3Si‐Cu microsphere@C composite can be ascribed to the improved electronic conductivity, enhanced mechanical stability, and better buffering against the large volume change in the repeated lithiation/delithiation processes.

Scalable Synthesis of Porous SiFe@C Composite with Excellent Lithium Storage

“…The high‐resolution Si 2p spectrum is shown in Figure 4 b. In the Si 2p spectrum, the peak at around 99.1 eV is attributed to the Si−Si bond, [28, 32] and the other two Si−C and Si−O bonds are located at 102.2 and 103.4 eV, [37, 38] respectively, indicating that partially SiO x (0< x <2) is formed on the surface of silicon [16] . The number of oxygen atom ( x ) on the silicon surface is about 1.08 by calculation.…”

“…proposed a Si/C shell cluster structure derived from a low‐cost industrial Al–Si alloy, demonstrating excellent long cycling stability with extremely low capacity loss in etch loop in the long cycle at high rate [30] . Our group also conducted the investigations on Al–Si alloys in situ coated with a metal–organic framework (MOF) and Cu modification; the as‐synthesized silicon‐based anodes, such as porous silicon microsphere@carbon, [20] porous Si–Cu 3 Si–Cu microsphere [31] and porous Si–Cu 3 Si–Cu microsphere@carbon, [32] exhibited outstanding lithium‐storage performance. Compared with Al–Si alloy, ferrosilicon as a deoxidizer and alloying agent is widely used in the steel‐making industry owing to its abundance and low price [33–35] .…”

Si-based Composite Anode for Li-ion Batteries with Enhanced Electrochemical Performance via CuCl2·2H2O Assisted Coating of PDA

“…In order to improve the performance of Si anode, one of the promising strategies is to make full use of synergistic effects of different aforementioned methods. Recently, Si-based anode materials with a unique structure of Si-MSi-M@C or Si-MSi@C (M = metal element) have been paid much attention and studied by many groups [17][18][19][20][21][22].…”

Tunable Synthesis of Hierarchical Yolk/Double‐Shelled SiOx@TiO2@C Nanospheres for High‐Performance Lithium‐Ion Batteries

“…[6][7][8][9] Therefore, the development of energy materials with stable physicala nd chemical properties, low cost, environmental friendliness,a nd electrochemical activity is an effective way to improvet he performance for energy storages ystems. [10][11][12][13][14][15][16][17] Metal oxidesa re ac urrent focus for research on lithium-ion battery anode materials. [18][19][20] Metal oxidesc an replacet he cur-rent commercial graphite anode materials because of their high theoretical discharge specific capacity,h igh powerd ensity,a nd abundant reserves.…”

“…Due to ever‐increasing demand, it is of critical importance to improve the energy density of rechargeable lithium‐ion batteries by various strategies in which developing high performance electrode materials is the most effective strategy [6–9] . Therefore, the development of energy materials with stable physical and chemical properties, low cost, environmental friendliness, and electrochemical activity is an effective way to improve the performance for energy storage systems [10–17] …”