Li-Ion-Batteries

Li-Ion batteries are rechargeable batteries and are very often used within modern electronic appliances as they are much lighter than other types of rechargeable batteries. Further they can hold their charges and do not have the so called memory effect, so they can handle hundreds of charge/discharge cycles. However, their lifetime is limited to 3-5 years. Therefore it is expected that the amount of Li-Ion-Batteries occurring in the waste stream is steadily increasing.

The active material of negative electrode of common li-ion batteries mainly contains of graphite. The positive electrode contains usually lithium metal oxide, e.g. LiCoO2, LiNixMnyCozO2, LiFePO4, or LiMn2O4.

Table 1 Composition of an average 10-12kg Li-ion battery (source: http://energyskeptic.com/2015/epa-lithiu...)

Due to the contained energy, it is possible that Li-ion Batteries get on fire which is usually caused by an internal short in the battery. This happens in case the separator of the battery is broken or got punctured. Since li-ion batteries are so energetic, they get very hot. The heat causes the battery to vent the organic solvent used as an electrolyte, and the heat (or a nearby spark) can light it. Once that happens inside one of the cells, the heat of the fire cascades to the other cells and the whole pack goes up in flames.

Caution during dismantling

Discarded Li-ion batteries often hold major residual charges leading to high probability of strong short circuits if not treated with caution. Therefore:

• NEVER short-circuit, open, dismantle, pierce, drop or squeeze Li-Ion batteries
• DO NOT use electrically conducting tools

Carefully remove Li-Ion batteries from the device. There is usually no difficulty or risk to separate the batteries from their support if they are in good condition. Use gloves and wash Hands. Throw the gloves away after contact with substances from defective and leaking batteries.

In order to prevent short circuits all batteries should be masked with common adhesive tape – at least 2-3 layers. Obviously broken Li-Ion batteries (e.g. inflated ones) should be handled with additional care and stored separately.

Storage

Lithium-ion batteries can easily rupture, ignite, or explode when exposed to high temperatures, or direct sunlight, therefore Li-Ion batteries should be stored at temperatures ranging from -20°C to 25°C. For save storage use a designated storage box. The box should be filled with inherent flame resistant material. The box should not be air-proof. Although a lid is required it should be compensative to pressure due to heat development.

Transportation

The transport of Li-ion batteries needs to follow the international regulations of transport of hazardous waste and dangerous goods. In Europe the ADR (European Agreement concerning the International Carriage of Dangerous Goods by Road -http://www.unece.org/trans/danger/publi/... ) guidelines for transportation on road and IMDG codes (International Maritime Dangerous Goods Codes) for sea transport need to be followed. Special transport boxes and labelling is required for the transport of Li-ion batteries. Further the preparation of a detailed packaging list (including number and type of packaging units, gross weight, net weight, type of material, lot reference, contract reference) is advisable and often required by the purchaser.

When shipping Li-Ion batteries abroad the requirements under the Basel Convention need to be fulfilled. Therefore be please be in contact with your corresponding authority to receive information regarding the required documentation and preparatory/ administrative work.

General indications concerning existing purchasers

A variety of battery recyclers exist world-wide. Usually those recyclers also treat Li-ion batteries. During the last years some recycling facilities developed specialized treatment processes for rechargeable batteries including Li-ion batteries. Due to their lifetime and their increasing use in electrical equipment and electric vehicles, it is expected that the quantities of rechargeable batteries will increase within the next decade.

List of available state of the art recycling technologies

Recycling of batteries is not new, but historically has been limited to the most common chemistries such as alkaline batteries, lead acid batteries and NiCd batteries. Therefore the recycling of Li-ion batteries is still in its infancy and standard recycling process is developed yet. The recycling of Li-ion batteries still needs further research and development. Some main recycling technologies are listed below:

1. Mechanical recycling process – After mechanical size reduction through a hammer-mill and a shaker table mixed plastics and metals are separated. Metals are then sentfor recycling, but the process in only economical if cobalt and/ or nickel is contained in the input material.
2. Pyrometallurgical processes (smelting) - Valuable metals are reduced to an alloy of copper, cobalt, nickel, and iron. Through further hydrometallurgical processing those metals can be recovered from the alloy. Other materials that were present in the cathode like lithium, aluminium, silicon, calcium and iron end up in the slag. Further recovery of aluminium or lithium from the slag is neither economically nor environmentally viable. The following table lists the recycling efficiency of Li-Ion batteries.

Table 2: Recycling efficiency of Li-Ion batteries.

As the treatment of Li-ion batteries is a costly operation and only small parts of valuable materials can be recovered, recycling facilities charge for their treatment. Depending on the composition of the input material costs are in a range of xxx USD / t

Gaines, L. The future of automotive lithium-ion battery recycling: Charting a sustainable course; Sustainable Materials and Technologies, Volumes 1-2 (2014)