---Heather Li
Email: sales04@chemfish.com
Tel/whatsapp: +8615073231317
Improving the cyclic stability of lithium metal anodes is of particular importance for developing high-energy-density batteries. In this work, a remarkable finding shows that the control of lithium bis(fluorosulfonyl)imide (LiFSI) concentrations in electrolytes significantly alters the thickness and modulus of the related SEI layers, leading to varied cycling performances of Li metal anodes.
In an electrolyte containing 2 M LiFSI, an SEI layer of ∼70 nm that is obviously thicker than those obtained in other concentrations is observed through in situ atomic force microscopy (AFM). In addition to the decomposition of FSI– anions that generates rigid lithium fluoride (LiF) as an SEI component, the modulus of this thick SEI layer with a high LiF content could be significantly strengthened to 10.7 GPa. Such a huge variation in SEI modulus, much higher than the threshold value of Li dendrite penetration, provides excellent performances of Li metal anodes with Coulombic efficiency higher than 99%.
Email: sales04@chemfish.com
Tel/whatsapp: +8615073231317
Improving the cyclic stability of lithium metal anodes is of particular importance for developing high-energy-density batteries. In this work, a remarkable finding shows that the control of lithium bis(fluorosulfonyl)imide (LiFSI) concentrations in electrolytes significantly alters the thickness and modulus of the related SEI layers, leading to varied cycling performances of Li metal anodes.
In an electrolyte containing 2 M LiFSI, an SEI layer of ∼70 nm that is obviously thicker than those obtained in other concentrations is observed through in situ atomic force microscopy (AFM). In addition to the decomposition of FSI– anions that generates rigid lithium fluoride (LiF) as an SEI component, the modulus of this thick SEI layer with a high LiF content could be significantly strengthened to 10.7 GPa. Such a huge variation in SEI modulus, much higher than the threshold value of Li dendrite penetration, provides excellent performances of Li metal anodes with Coulombic efficiency higher than 99%.
Our approach demonstrates that the FSI– anions with appropriate concentration can significantly alter the SEI quality, establishing a meaningful guideline for designing electrolyte formulation for stable lithium metal batteries.
While lithium bis(fluorosulfonyl) imide (LiFSI) is widely used in current Li-ion batteries (LIBs), the role of LiFSI in the LIB performance remains elusive.
An in-depth electrochemical analysis using graphite/Li half cells and graphite/graphite symmetric cells confirms that LiFSI provides little improvement to the cyclability of the graphite anode at 25 °C, but enables far better performance in cycle and storage tests at 60 °C. The superior thermal stability of the graphite anode in LiFSI electrolyte is attributed to the formation of a thin, inorganic-rich solid electrolyte interphase (SEI) layer as indicated by differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS) measurements.
LiFSI is an ideal additive to improve the service life of batteries in high temperature and low temperature environments. Many literatures have studied and proved this.
Company profile >
*Chemfish is an innovation chemical supplier, owns a laboratory with more than 50 doctors for new formula development.
*We specialized in variety of Chemicals, such as: Polymer additive, Electrolyte Additive, Specialty materials, Intermediates. We'd very glad to help you find the best quality and suitable product.
评论
发表评论