A Basic Safe Handling Guide for Stabilized Lithium Metal Powder (Lectro Max Powder)
Disclaimer In preparing this guide, FMC Lithium has utilized the best information known and available at the time of printing. FMC Lithium recognizes that over time techniques, methods and equipment related to the safe handling of lithium metal will evolve, dating the information within this guide. Additionally, the information presented in this Guide has been written to address most typical situations, environments and facilities, based upon FMC Lithium s experiences. However, FMC Lithium recognizes that each customer s situation is different and necessitates specific solutions to fit those requirements. This guide is intended to assist in the handling of small quantities of SLMP in a laboratory environment. FMC Lithium seeks to provide up-to-date solutions to the questions or concerns that our customers may have. Please contact us to discuss your specific needs.
Responsible Care FMC supports the principles of the American Chemistry Council (ACC) Responsible Care program by working with our employees, suppliers, customers, contractors, and commercial partners to promote responsible management of products and processes.
Outline Introduction Properties of Lithium Metal Laboratory Safety Application Methods for SLMP (Lectro Max Powder) Specifications
Introduction This guide is provided for the application and use of Stabilized Lithium Metal Powder (SLMP ). Non-stabilized lithium metal powder is pyrophoric, has to be stored under heavy organic oils, is dangerous to handle, and requires special handling and environmental conditions. SLMP is non-pyrophoric, can be transported by air and sea and can be handled with care under controlled environmental conditions. SLMP is protected by US Patents 5,567,474; 5,776,369; 6,706,447; 7,588,623 and other patents pending, and is not for commercial purposes. This product is for Research and Development only.
Introduction SLMP provides an independent source of lithium for Li-ion Batteries. Breaks the current limitation that all Li has to come from the cathode and is more cost effective than Li supplied from LiCoO 2 Allows the use of non-lithium providing cathode materials that are more overcharge tolerant with potentially larger capacities SLMP can be applied in existing Li-ion cell designs by partially lithiating the anode to compensate for the irreversible capacity of the graphite or other anode materials Allows 5%-15% improvements in cell capacity without a voltage change.
Properties of Lithium Metal Li [He]2s 1 6.941 Lithium 3 Lithium is a somewhat soft, silver-white metal in elemental form Lithium is the lightest metal (d=0.534 g/cm 3 ) Lithium has a high electrochemical potential (more negative standard electrode potential relative to SHE) Lithium metal is flammable and air and water sensitive
Properties of Lithium Metal Lithium metal, like other alkali metals, is very reactive toward water and air. The degree of the metal s reactivity is proportional to its surface area. Large pieces of lithium metal will react relatively slowly with air and water while lithium metal as a finely divided powder can react very rapidly. 2 Li + H 2 O Li 2 O + H 2 Lithium will react with nitrogen in the air to form lithium nitride. This reaction is catalyzed by the presence of moisture in the air. Lithium should be stored under argon. 6 Li + N 2 2 Li 3 N For this reason, lithium metal is usually handled under argon, in oil and/or in a dry room. Even in a dry environment, however, finely divided dry lithium powder will react with the oxygen in the air unless it is protected with an inert coating - like those on our SLMP. These coatings allow even finely divided lithium metal powder to be handled in a dry room environment for extended periods of time. 4 Li + O 2 2 Li 2 O
Handling of SLMP While SLMP has a coating that mitigates many of the difficulties with handling lithium metal powder, precautions are still required with its handling: SLMP will still react with water SLMP is dusty care should be taken not to inhale this dust as it is very irritating to mucous membranes SLMP can react with moisture in the skin and eyes to cause irritation or burns SLMP should be stored in a closed container under an inert atmosphere when not in use SLMP may be incompatible with other chemicals
Handling of SLMP Detailed information on material hazards, handling and storage is provided in the New Product Data Sheet (NPDS). We recommend the following PPE Safety glasses Dust mask Gloves Nomex (fire retardant) laboratory coat Fume hoods
Li, % Handling of SLMP It is best to handle SLMP in a dry room atmosphere. Studies conducted at -30 o C dew point show <1% loss in metallic lithium content after 50 hours. Dry Room Conditions DP=-30 o C 100 80 60 40 20 0 0 50 100 150 200 250 300 Time, hours
Compatibility of SLMP SLMP is incompatible with some other chemicals. Users should exercise caution when mixing SLMP with other chemicals. Some compatibility data is available from FMC Lithium upon request. SLMP compatibilities to consider: Solvents Binders Electrolytes Substrates Moisture in chemicals
Fire Fighting SLMP is designed to be non-pyrophoric but it is still combustible. Any area where SLMP will be handled should be equipped with one of the following fire extinguishers: Copper powder Graphite Lith-X Dry sodium chloride Dry calcium oxide Dry lithium chloride X Never use water, sand or carbon dioxide
Disposal Of Waste Materials It is essential that all equipment and waste materials containing the lithium powder are de-activated prior to disposal. Good house-keeping is vital for safe operation with the powder. The powder reacts with water to produce heat and hydrogen gas, according to the equation: Li (s) + H 2 O LiOH + ½ H 2 (g) The hazard depends on the quantity of lithium present, and the form of the material. For example, coated electrodes are safer than the pure powder.
Disposal Of Waste Materials Small quantities of SLMP may be left in storage bottles, or in equipment used to transfer the powder. If they are enclosed (e.g. in bottles), then they should be transferred to a well-ventilated area (e.g. a fume cupboard) and be slowly de-activated with wet air. After a few hours, the powder will have hydrolyzed. The bottle can then be washed out, to produce dilute lithium hydroxide. If the powder is not enclosed, then it is best not to try to transfer it (electro-static forces will tend to disperse the powder). Small quantities can be allowed to react with isopropyl alcohol or t-butyl alcohol.
Disposal Of Waste Materials It is best not to try to de-activate the lithium while a mix still contains solvent. Vessels should be placed in a location where it is safe for the solvent to evaporate. The dry coating residue can then be treated like electrode off-cuts, as described in the following section. Residue in the coating head should also be allowed to dry out, before being scraped off. Surfaces can be washed with isopropyl alcohol, and then wiped with tissues. Lithium is safe when stored under mineral oil. Small amounts can be wiped up with an oil-soaked cloth.
Disposal Of Waste Materials Off-cuts from electrode cutting and cell winding, coating residues, and cleaning tissues should all be deactivated in the same way. The preferred method is to use a tank containing water, with a layer of mineral oil on top of it. The electrode materials are lowered into the bath using a basket arrangement. Given the reaction between the lithium powder and water, it is essential that the off-gas from the tank is purged e.g. with nitrogen. Ventilation will also need to be to a safe area, where the hydrogen can be dispersed or reacted in a controlled manner.
Disposal Of Waste Materials The preferred method to de-activate lithium powder which has been applied to the surface of an electrode is to transfer the electrode to a well ventilated area with wet air (e.g. a fume cupboard). After a few hours, white spots of lithium hydroxide will appear. The electrode can then be disposed of through normal disposal routes.
SLMP Application Methods Surface application - an SLMP suspension is applied to a prefabricated anode sheet Slurry application - a conventional electrode preparation method is employed and both binder and solvent must be compatible (non-reactive) with lithium.
Surface Application Method Surface application is where an SLMP suspension is applied to a prefabricated anode sheet. The techniques include, for example, dip coating, draw-down coating, spray coating, sieving and painting onto the pre-fabricated electrodes. Optimization of the suspension formulation for the surface application is a critical task. Consideration should be given to: 1) Compatibility of SLMP, solvent and additives 2) Physical properties of the solvent to fit the desired process conditions 3) Proper additive selection to ensure suspension homogeneity and stability 4) Concentration of the suspension components. The choice of the suspension formulation additives depends on the specific technique selected and a need to keep SLMP suspended in the mix. Also, the specific properties of the anode film should be taken into consideration.
Slurry Application Method Formation of an anode is achieved by combining SLMP, a fine particle host material, a binder polymer, and a solvent to form a slurry. The slurry can be coated on a current collector, such as copper foil or mesh, and dried. Examples of host materials: Carbonaceous materials such as: Graphite Hard Carbon Silicon, tin and other composites
Standard SLMP Specifications Free Lithium Content: Particle Size (D50): Li 2 CO 3 Content: 97% min. <50 micron 0.5% min. Trace Elements (max ppm): Nitrogen: 500 Chloride: 100 Calcium: 300 Iron: 300 Potassium: 100 Sodium: 300 Silicon: 300
For Further Information Dr. Chris Woltermann, Product and Technology Development Manager Chris.woltermann@fmc.com Bruce Urban, Global Product Manager Bruce.urban@fmc.com http://fmclithium.com/ FMC, Lectro and SLMP are trademarks of FMC Corporation Nomex is a product of DuPont Lith-X is a product of Ansul Inc. 2010 FMC Corporation