A Cost‐Effective and Scaleable Approach for the In‐Situ Synthesis of Porous Carbon‐Coated Micrometer‐Sized AlSi Particles as Anode for Lithium‐Ion Batteries

Formicarium-Like Micron Porous Si Synergistically Adjusted by Surface Hard-Soft Nanoencapsulation as Long-Life Lithium-Ion Battery Anode

Micron porous silicon (MPSi) is a promising lithium-ion battery (LIB) anode that can provide enough space to effectively alleviate the volume expansion and large number of transmission channels to rapidly transport the Li-ions. However, a long-term stable MPSi anode at high current density is still a great challenge. Herein, a double-regulated formicarium like-MPSi composite using the surface hard-soft titanium dioxide-few layered MXene nanotemplate (FMPSi@TiO2@FMXene) was designed and synthesized via an in situ assembly strategy as long-life LIB anode. Such hard-soft TiO2-FMXene nanoencapsulation can collaboratively tune the internal/external stress, inhibit the volume expansion, reduce the interfacial reactions, and improve the electrical conductivity of MPSi, resulting in the great enhancement of structural stability and electrochemical performance in cycling even at high current density. Especially, this FMPSi@TiO2@FMXene anode exhibits a high reversible capacity of 1254.9 and 970.4 mAh/g after 500 cycles at 0.5 and 1 A/g, respectively. Moreover, a full cell is assembled with the FMPSi@TiO2@FMXene anode and commercial LiFePO4 (LFP) cathode, exhibiting a high capacity retention rate of 91.6% in 100 cycles. This work provides an effective surface nanoengineering tactic to obtain the structurally stable MPSi anodes by hard-soft nanotemplate for large-scale and long-term LIB application.

Low-cost urchin-like silicon-based anode with superior conductivity for lithium storage applications

Poor rate and cycling performance are the most critical drawbacks for Si-based anodes on account of their inferior conductivity and colossal volumetric expansion during lithiation/delithiation. Here we report the fabrication of structurally-integrated urchin-like Si anode, which provides prominent structural stability and distinguished electron and ion transmission pathways for lithium storage. The inexpensive solid Si waste from organosilane industry after acid-washed and further ball-milling serves as the pristine Si-source in this work. Carbon nanotubes (CNTs) are in-situ grown outside Si microparticles, resulting in an urchin-like structure (Si/CNTs). The optimized Si/CNTs presents ascendant invertible capacity and rate performance, achieving up to 920 mAh g^-1 beyond 100 cycles at 100 mA g ^-1, and a capacity of 606.2 mAh g^-1 at 1 A g ^-1 after long cycling for 1000 cycles. The proposed scalable synthesis can be adopted to advance the performance of other electrode materials with inferior conductivity and enormous volume expansions during cycling.