The present study describes a novel strategy for preparing thin Silicon 2D and 3D electrodes for lithium ion batteries by a spin coating method. A homogeneous and stable suspension of Si nanoparticles (SiNPs) was prepared by dispersing the nanoparticles in 1-methyl-2-pyrrolidone (NMP) or in the room temperature ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (Pyr14T...

The unstable solid–electrolyte interphase (SEI) on Li anodes is the origin of major performance challenges in batteries, namely, insufficient Coulombic efficiency (CE) and cycle life. While it known that SEI participates aging processes, pinpointing chemical origins by tracing them to specific phases has been experimentally challenging. Here, we formed single-phase, thin (<50 nm) interfaces Li2...

A comprehensive model has been developed for calculating electrical conductivities of aqueous or mixed-solvent electrolyte systems ranging from dilute solutions to fused salts. The model consists of a correlation for calculating ionic conductivities at infinite dilution as a function of solvent composition and a method for predicting the effect of finite electrolyte concentration. The effect of...

Silicon has been widely considered as the next generation anode material for lithium-ion batteries, due to its substantially higher capacity compared to conventionally used graphite. However, silicon-based electrodes suffer from problems such as poor capacity retention and low coulombic efficiency. Significant amount of work has been devoted to improve the performance of silicon electrodes. Amo...

To improve the energy density of lithium-ion batteries, development advanced electrolytes with enhanced transport properties is highly important. Here, we show that by confining conventional electrolyte (1 M LiPF6 in EC-DEC) a microporous polymer network, cation transference number increases to 0.79 while maintaining an ionic conductivity on order 10−3 S cm−1. By comparison, non-porous, condens...

Environmentally friendly and cost-effective Li-ion cells are fabricated with abundant, non-toxic LiFePO4 cathodes and iron oxide anodes. A water-soluble alginate binder is used to coat both electrodes to reduce the environmental footprint. The critical reactivity of LiPF6 -based electrolytes toward possible traces of H2 O in water-processed electrodes is overcome by using a lithium bis(oxalato)...

BACKGROUND Advance Technology Development (ATD) Program is a new program put forth by Department of Energy to develop high power lithium ion batteries for hybrid electric vehicles and electric vehicles. It is a joint effort of five national labs and LBNL is the lead lab in investigating SEI (solid electrolyte interface) layer formation and dissolution. Our group is responsible for the character...