Battery-Based Energy Storage Systems for Stationary Applications Hans Desilvestro Hanmer Springs November 2004
Outline Battery ESS selection criteria The raw materials issue The LiOX battery Safe Li-ion type battery based on oxide active materials Cost comparison of commercially available and emerging energy storage systems (ESS) Summary
Courtesy Dr Paul Rüetschi
Battery ESS selection criteria Specific Energy (Wh/kg) - to + Energy Density (Wh/L)+/- to + Power performance (W/kg, W/L) - Cycle life and calendar life + $/year ++ Safety ++ Maintenance-free $-issue
Economic and safety considerations more important than other performance parameters
Factors influencing raw material costs Natural abundance / mineable sources Mining / refining costs Demand in key markets Commodity vs speciality markets Relative importance of battery market in relation to key markets Common ore origin e.g. Fe-Ni-Co or Zn-Cd Ease of recycling
%
Are Li-ion batteries safe ? Ask IATA: Li-ion battery size for carry- on items limited to 100 Wh Even small portable Li-ion batteries encounter safety problems quite frequently Overheating, fire, explosions, product recalls Limiting maximum thickness or diameter to max. ~16 mm Li-ion batteries can only be operated in a relatively safe way by - electronic single cell control - safety elements such as burst disks, PTC,...
Reasons for relatively poor safety characteristics of standard Li-ion batteries Overall cell reaction: 3C + LiCoO 2 0.5C 6 Li + Li 0.5 CoO 2 Charge to 4.2V Discharge to ~3V Thermodynamically unstable O 2 + LiCo-oxides + heat Very close to Li plating potential Thermodynamically unstable towards solvents employed
Reasons for relatively poor safety characteristics of standard Li-ion batteries
Pacific Lithium saw market opportunities for a safe Li-ion type battery LiOX
LiOX, a safe Li-ion battery Overall cell reaction: Li 3 Ti 5 O LiMn 2 O 4 Charge to 2.7V Discharge to 2.2V Thermodynamically much more stable than Li 0.5 CoO 2 No risk of Li plating Thermodynamically stable towards solvents employed Li 7 Ti 5 O Mn 2 O 4
Cycle Life of 5-cell batteries at 22, 45 o C, 55 o C. 1C charge and discharge (100%)
Conclusions