Synthesizing copper-doped silicon/carbon composite anode as cost-effective active materials for Li-ion batteries

Potentially useful anodic material with prospects for use within rechargeable lithium-ion batteries are fabricated from silicon (Si)-based compounds. The active Si/electrolyte contact and weak conductivity, however, constantly produce side reactions, which dramatically reduce cycling stability. The only metallic current collector that demonstrates to facilitate lithium-ion transfer and electron conduction without alloying reactions is copper (Cu). In this study, we created Si-based multicomponent anode materials made of Si/Cu/Cu3Si alloy nanoparticles (Si/ Cu/Cu3Si@C) coated in amorphous carbon. This is accomplished utilizing a straightforward, low-cost approach that combines hydrothermal technology and high-intensity ball milling. To further increase conductivity, Si/Cu/ Cu3Si alloy is used as the active component. Through the use of a micro-sized amorphous carbon-coated structure, the volume problem of the active material can be successfully resolved. Additionally, the micro-sized amorphous carbon may inhibit nanoparticle agglomeration and alloy interfacial side reactions. As a result, it is anticipated that the Si/Cu/Cu3Si@C composite will display favorable electrochemical performances and possess a remarkable reversible specific capacity of 984 mAh g- 1 at 0.5 C. The GITT test is used to determine the DLi+ of the Si/Cu/Cu3Si@C electrode, which ranges from 10-11 to 10-8 cm- 2 s- 1. Additionally, the full-cell is constructed by coupling a Li(Ni1/3Co1/3 Mn1/3)O2(NCM111) cathode with a solution-based chemically Si/Cu/ Cu3Si@C anode that exhibits an enhanced initial coulombic efficiency (84.9%) and outstanding cycle performance.

Automated summary

In this study, Si/Cu/Cu3Si@C composite materials were fabricated as anode materials for lithium-ion batteries using a low-cost hydrothermal technology and high-intensity ball milling. The volume problem of the active material was successfully resolved by using a micro-sized amorphous carbon-coated structure, and the agglomeration of nanoparticles and alloy interfacial side reactions were inhibited. The Si/Cu/Cu3Si@C composite is expected to exhibit favorable electrochemical performances and possess a remarkable reversible specific capacity. A full cell was constructed by coupling the Si/Cu/Cu3Si@C anode with a Li(Ni1/3Co1/3Mn1/3)O2(NCM111) cathode, showing excellent cycle performance and enhanced initial coulombic efficiency.