1. Lithium Sulfur Batteries
Presented by Timothy Cleary
Oral English Assessment Exam

2. A brief two part presentation: 1. Review of LFP batteries 2
A brief two part presentation: Review of LFP batteries Introduction to Li-S batteries

3. Review of Lithium Iron Phosphate Batteries

4. Electrospun Nanofiber-Based Anodes, Cathodes, and Separators for Advanced Lithium-Ion Batteries

5. Electrospun Nanofiber-Based Anodes, Cathodes, and Separators for Advanced Lithium-Ion Batteries

6. Electrospun Nanofiber-Based Anodes, Cathodes, and Separators for Advanced Lithium-Ion Batteries

7. LFP – Charge / Discharge Voltage Curve

8. Introduction to Lithium Sulfur Batteries

9. Interesting Voltage Curve
Tight voltage range (2.5 to 1.4 V)
Different charge/discharge profiles
Discharge - S8 to Li2S
(2.3V) High plateau reduction of long chain lithium polysulfides (Li2Sx, 4 <= x)
(2.1V) Low plateau reduction of short chain lithium polysulfides (Li2Sx, x <= 4)
Charge - Li2S to S8
(Copyright 2013, Royal Society of Chemistry)

10. High Energy Density (G. Zhou)
This Ragone plot shows how Li-S battery performance compares to other popular electrical energy storage systems. On par with the energy density of a fuel cells and the power density of Li-Ion batteries 5x specific energy of Li-Ion (theoretical) 2500 (Li-S) vs 500 (Li-ion) [Wh/kg]
(G. Zhou)

11. Sulfur
Inexpensive
Non toxic
10th most abundant element

12. Safety Performance
Impressive nail puncture performance, no smoke and almost no energy release

13. What cause this cell to fail?
Shuttle effect / Sulfur insulation
The soluble polysulfide intermediates (Li2Sx, 3 ≤ x ≤ 8) in the organic liquid electrolyte during the cycle process bring about the polysulfide “shuttle effect,” which leads to irreversible capacity loss and corrosion on the lithium–metal anode [Yang, Wang].
Insulating characteristic of sulfur and its discharge products (Li2S), leading to a low utilization of active material [Wang];
Structural instability
Large volumetric expansion/shrinkage (80%) during discharge/charge due to the different densities of sulfur (2.03 g cm−3) and lithium sulfides (1.67 g cm−3), resulting in an instability of the electrode structure;
As a result, todays realistic life of a LiS cell is about 500 to 1000 cycles

14. Research Goals In preparation for when Li-S cells become commercially available
Modeling & characterization
Application of observers/estimators for SOC prediction
Life cycle optimization

15. Companies Making Li-S Cells
OXIS Energy – Achieving ~ 500 cycle and bosting 400 Wh/kg
SAFT – Li SO2 (primary battery)
Sony – Announces plans for commercialization of lithium- sulfur (Li-S) / magnesium sulfur (Mg-S) by 2020

16. References 2017_Book_DesignFabricationAndElectroche
© Springer Nature Singapore Pte Ltd. 2017
G. Zhou, Design, Fabrication and Electrochemical Performance of Nanostructured
Carbon Based Materials for High-Energy Lithium–Sulfur Batteries, Springer Theses,
DOI / _1
OXIS Energy -
Wang D-W et al (2013) Carbon-sulfur composites for Li–S batteries: status and prospects. J Mater Chem A 1(33):9382–9394
Wang D-W et al (2012) A microporous-mesoporous carbon with graphitic structure for a high-rate stable sulfur cathode in carbonate solvent-based Li–S batteries. Phys Chem Chem Phys 14(24):8703–8710
Yang Y, Zheng G, Cui Y (2013) Nanostructured sulfur cathodes. Chem Soc Rev 42(7):3018–3032