Control of Surface Chemistry and Electrochemical Performance of Carbon-coated Silicon Anode Using Silane-based Self-Assembly for Rechargeable Lithium Batteries

Abstract

Silane-based self-assembly was employed for the surface modification of carbon-coated Si electrodes and their surface chemistry and electrochemical performance in battery electrolyte depending on the molecular structure of silanes was studied. IR spectroscopic analyses revealed that siloxane formed from silane-based self-assembly possessed Si-O-Si network on the electrode surface and high surface coverage siloxane induced the formation of a stable solid-electrolyte interphase (SEI) layer that was mainly composed of organic compounds with alkyl and carboxylate metal salt functionalities, and PF-containing inorganic species. Scanning electron microscopy imaging showed that particle cracking were effectively reduced on the carbon-coated Si when having high coverage siloxane and thickened SEI layer, delivering > 1480 mAh/g over 200 cycles with enhanced capacity retention 74% of the maximum discharge capacity, in contrast to a rapid capacity fade with low coverage siloxane.

Strategies for Building Robust Traffic Networks in Advanced Energy Storage Devices: A Focus on Composite Electrodes

“…For example, for Li 4 Ti 5 O 12 , carbon coating can significantly improve the C‐rate performance, cycle stability as shown Figure e, and stability with electrolyte . For big‐volume‐change electrode particles (e.g., silicon), carbon coating is also critical for stabilizing the ETN structures and SEI layer . However, it should be noted that for silicon, carbon‐coating is usually combined with a rational design of pore structure inside the particles to compensate the big volume change.…”

Studies of Lithium Diffusivity of Silicon-Based Film Electrodes for Rechargeable Lithium Batteries

“…2,3) It has been established that interfacial instability of Si electrode with electrolyte, i.e., the attack of LiPF 6 -derived acidic species (PF 5 , PF 3 O, HF) addi-tionally deteriorate the particle cracking event. [4][5][6] Our earlier work showed that for amorphous silicon suboxides, SiO x (x = 0.4, 0.85, 1.0 and 1.3), higher oxygen content induces to decrease initial electrolyte reduction but larger fraction of oxides is subjected to dissolution by acid (e.g., HF)-etching. 7) The control of anode-electrolyte interfacial reaction and the formation and composition of solid electrolyte interphase (SEI) has been suggested as an effective approach for enhancing the cycling performance of Si-based anodes for rechargeable lithium batteries.…”

“…7) The control of anode-electrolyte interfacial reaction and the formation and composition of solid electrolyte interphase (SEI) has been suggested as an effective approach for enhancing the cycling performance of Si-based anodes for rechargeable lithium batteries. [4][5][6][7][8][9][10] Lithium diffusivity is an intrinsic property of lithium ion-conducting electrode material. It is generally proposed that the rate of lithiation process of anode and cathode material is controlled by lithium diffusion.…”

“…Tasaki 17) Studies of dense film model electrode can give a clearer insight into the intrinsic properties of electrode material without complications from the carbon and polymeric binder additives that are necessary in bulk electrodes for enhanced electric conductivity and particle connection. [4][5][6][7][8][9][10]18) Our earlier work showed that interfacial stabilization of pulsed laser deposited (PLD) Si film model electrode on Cu substrate by constructing the surface protective siloxane network at the electrode surface using dimethoxydimethylsilane (DMMS, (CH 3 ) 2 (CH 3 O) 2 Si) provides lithium diffusivity of 2.35×10 13 cm 2 /s which is approximately three orders lower than ~1.12×10 10 cm 2 /s of graphite powder electrode. 5,19) Nanometer-scale film electrode deposited homogeneously on a conductive substrate can have a robustness to structural and mechanical changes with cycling before disintegration and strong adherence to the substrate, yielding a good model system for the study of lithium diffusion kinetics during electrochemical cycling.…”

Studies of Lithium Diffusivity of Silicon-Based Film Electrodes for Rechargeable Lithium Batteries

“…[4][5][6][7][8][9][10]18) Our earlier work showed that interfacial stabilization of pulsed laser deposited (PLD) Si film model electrode on Cu substrate by constructing the surface protective siloxane network at the electrode surface using dimethoxydimethylsilane (DMMS, (CH 3 ) 2 (CH 3 O) 2 Si) provides lithium diffusivity of 2.35×10 13 cm 2 /s which is approximately three orders lower than ~1.12×10…”