Si–CNT/rGO Nanoheterostructures as High‐Performance Lithium‐Ion‐Battery Anodes

Abstract

A robust and electrochemically stable 3D nanoheterostructure consisting of Si nanoparticles (NPs), carbon nanotubes (CNTs) and reduced graphene oxide (rGO) is developed as an anode material (Si–CNT/rGO) for lithium‐ion batteries (LIBs). It integrates the benefits from its three building blocks of Si NPs, CNTs, and rGO; Si NPs offer high capacity, CNTs act as a mechanical, electrically conductive support to connect Si NPs, and highly electrically conductive and flexible rGO provides a robust matrix with enough void space to accommodate the volume changes of Si NPs upon lithiation/delithiation and to simultaneously assure good electric contact. The composite material shows a high reversible capacity of 1665 mAh g−1 with good capacity retention of 88.6 % over 500 cycles when cycled at 0.5 C, that is, a 0.02 % capacity decay per cycle. The high‐power capability is demonstrated at 10 C (16.2 A g−1) where 755 mAh g−1 are delivered, thus indicating promising characteristics of this material for high‐performance LIBs.

Conjugation with carbon nanotubes improves the performance of mesoporous silicon as Li-ion battery anode

“…1° Physical mixing in ethanol. 2° Conjugation with carbodiimide compound (1-ethyl-3-(3-dimethylaminopropyl)carboimide (EDC) crosslinker and N-hydroxysuccimide (NHS), activator) where amine and carboxylic groups are bound together by forming an amide group 22 .…”

Parasitic Reactions in Nanosized Silicon Anodes for Lithium-Ion Batteries

“…Si NPs were synthesized in N 2 using a tubular hot-wall reactor (HWR, inner diameter 14 cm) and pure monosilane (SiH 4 , quality EHP, Air Liquide) as the precursor. The experimental procedure was described in our previous work. , In brief, SiH 4 gas was fed into the reaction-tube through a concentric nozzle that is mounted at the top of the HWR. A coaxial H 2 gas flow (quality 5.0, Air Liquide) served as a sheath gas to prevent the decomposition of SiH 4 on the reactor-wall.…”

An in situ iodine-doped graphene/silicon composite paper as a highly conductive and self-supporting electrode for lithium-ion batteries

“…In addition, a broad peak located at about 0.4-0.7 V (vs. Li + / Li) is different from that of subsequent cycles and attributed to the formation of an SEI-layer on the electrode. 46,47 In the second cycle, the peak at around 0.2 V in the discharge process, which is accepted as the phase change of Si from crystalline to amorphous during the rst cycle. During the subsequent charging process, two anodic branches are located at 0.3 and 0.5 V corresponding to the de-lithiation process of amorphous Li x Si.…”