All Silicon Lithium-ion Battery Chao Xu Department of Chemistry-Ångström Uppsala University.

All Silicon Lithium-ion Battery

Chao XuDepartment of Chemistry-Ångström

Uppsala University

Project info.

• Projektets namn: Nästa generation litium-jon batterier; kisel och silikat

• Start- och sluttid för projektet: 2011-06-01 – 2014-12-31

• Huvudstödmottagare samt andra parter i projektet: Torbjörn Gustafsson, UU

• Inom vilket program projektet fått stöd: Energieffektiva vägfordon, period 2011-2014

• Stödsumma: 4920000 kr

Background

1. Tarascon, J. M. and M. Armand (2001). "Issues and challenges facing rechargeable lithium batteries." Nature 414(6861): 359-367.

Criteria for different systems

• Portable devices

• Electric vehicle

• Grid energy storage

Energy densitySafetyLifetime

Safety, lifetimePower density&Energy densityCost

LifetimeCostUp-scale capability

•Novel materials•Material modification•New electrolyte, additives•Battery system engineering

All Silicon Battery

• Battery configuration

Cathode Electrolyte Anode

Lithium metal silicate

e.g. Li2FeSiO4

Liqiud electroyte,polymer

electrolyteSilicon

Why ”all silicon”?

Silicate materials: stable crystal-structureEarth abundant elements - Si, (Fe) - Low cost -

Capable of large-scale productionHigh specific capacityLi2FeSiO4 166 mAh/g (LiCoO2 140 mAh/g )

Silicon 3600 mAh/g (Graphite 372 mAh/g )Environmentally friendly, compare to toxic LiCoO2

Problems to be solved

• Cathode side (Li2FeSiO4): Poor electronic conductivity Low temperature performance Extracting second Li from Li2FeSiO4

• Anode side (Si): Volume change during cycling (4 times larger when fully

discharged) Large irreversible capacity Low coulombic efficiency Capacity fading

Silicon anode

• Significantly increased capacity rentation and coulombic efficiency

10 wt% electrolyte additive (fluoroethylene carbonate, FEC) added in the electrolyte LP40

0.12 V – 0.9 V, 500 mA/g

Silicon anode

Solid electrolyte interphase (SEI) study using X-ray photoelectron spectroscopy (XPS)

After 85 cyclesC1s

FEC/LP40

LP40

Lithium iron silicate

• Combustion synthesis of Li2FeSiO4 (LFS) by Dr. Mohammed Dahbi

2. Dahbi, M., S. Urbonaite, et al. (2012). "Combustion synthesis and electrochemical performance of Li 2FeSiO4/C cathode material for lithium-ion batteries." Journal of Power Sources 205(0): 456-462.

All silicon battery

Preliminary results on silicate-silicon battery with different cycling conditions

Conclusion and Outlook

• Safe and long lifetime battery systems needed for EV application

• Electrolyte additive FEC can significantly increase the performance of silicon anode

• Improve the electronic and ionic conductivity of Li2FeSiO4 electrode

• Improve the all silicon battery performance

Acknowledgements

• Torbjörn Gustafsson• Kristina Edström• Mohammed Dahbi• Fredrik Lindgren• Bertrand Philippe

Comments and questions are appreciated!