Nano- and bulk-silicon-based insertion anodes for lithium-ion secondary cells

A review of the electrochemical performance of alloy anodes for lithium-ion batteries

The structural changes in silicon electrochemically lithiated and delithiated at room temperature were studied by X-ray powder diffraction. Crystalline silicon becomes amorphous during lithium insertion, confirming previous studies. Highly lithiated amorphous silicon suddenly crystallizes at 50 mV to form a new lithium-silicon phase, identified as This phase is the fully lithiated phase for silicon at room temperature, not as is widely believed. Delithiation of the phase results in the formation of amorphous silicon. Cycling silicon anodes above 50 mV avoids the formation of crystallized phases completely and results in better cycling performance. © 2004 The Electrochemical Society. All rights reserved.

https://iopscience.iop.org/article/10.1149/1.1652421/pdf

Structural changes in silicon anodes during lithium insertion/extraction

Alloy negative electrodes for Li-ion batteries.

In order to address power and energy demands of mobile electronics and electric cars, Li-ion technology is urgently being optimized by using alternative materials. This article presents a review of our recent progress dedicated to the anode and cathode materials that have the potential to fulfil the crucial factors of cost, safety, lifetime, durability, power density, and energy density. Nanostructured inorganic compounds have been extensively investigated. Size effects revealed in the storage of lithium through micropores (hard carbon spheres), alloys (Si, SnSb), and conversion reactions (Cr(2)O(3), MnO) are studied. The formation of nano/micro core-shell, dispersed composite, and surface pinning structures can improve their cycling performance. Surface coating on LiCoO(2) and LiMn(2)O(4) was found to be an effective way to enhance their thermal and chemical stability and the mechanisms are discussed. Theoretical simulations and experiments on LiFePO(4) reveal that alkali metal ions and nitrogen doping into the LiFePO(4) lattice are possible approaches to increase its electronic conductivity and does not block transport of lithium ion along the 1D channel.

Research on Advanced Materials for Li‐ion Batteries

http://ws2.binghamton.edu/me/Zhou/Zhou-publications/Solid-state-ionics.pdf

The crystal structural evolution of nano-Si anode caused by lithium insertion and extraction at room temperature

Li/Ag and Li/Al electrochemical cells composed of smooth Ag or Al electrode sheets, respectively, and matched with nonaqueous electrolytes were assembled and discharged. Discharged Ag electrodes were investigated using micro-Raman spectromety. Raman bands attributed to the components of the passivating film on the surface of the discharged Ag electrode, such as Li2CO3 and other species, were observed. No characteristic bands from discharged Al electrodes were present in the Raman spectra. This indicates that the Raman signals for the passivating layer are surface-enhanced by discharged Ag electrodes. The formation of a nanometer-scale rough surface caused by a Li−Ag alloy reaction during the discharging process is an important factor in the enhancement. It was also shown that the passivating films formed in various electrolytes could be distinguished by SERS.

Ning Pei

Papers

The crystal structural evolution of nano-Si anode caused by lithium insertion and extraction at room temperature

Surface-Enhanced Raman Scattering Study on Passivating Films of Ag Electrodes in Lithium Batteries†