One of the things that you should consider when putting battery storage on your home is whether or not the battery will be recyclable at the end of its life.
Recycling batteries at the end of their life has a number of benefits:
- It enables the recovery and reuse of materials including lead, iron, plastics, aluminium, copper, lithium, cobalt and electrolyte
- It diverts toxic and hazardous materials from landfill
- It ensures that batteries are managed safely
- There may be a financial return (depending on the battery type).
Often, one of the reasons that people put solar panels on their house and put in battery storage to collect the excess usage is to protect the environment and reduce the need for coal powered power stations. This can be counterproductive if you choose a battery that is made from toxic materials or has components that can’t be recycled at end of life of the battery.
When batteries go to landfill toxic substances can cause damage to the waste stream, waterways, humans and the general environment. This can be nickel, cadmium, lead or lithium ion.
Some countries have instituted laws that require an approved stewardship plan for the disposal of used batteries, however currently they only cover lead acid and small lithium ion of Nickel cadmium batteries. If these stewardship requirements are instituted for new energy storage batteries the cost will need to be included in the purchase cost of the batteries but some companies will avoid this responsibility as long as they can.
- Alkaline and lead acid batteries are projected to increase by 15% by 2019 – 2020
- Nickel metal hydride and nickel cadmium acid batteries are projected to increase by 25% by 2019 – 2020
- Sealed lead acid batteries are projected to increase by 50% by 2019 – 2020
- Lithium ion batteries are projected to increase by 300% by 2019 – 2020
Recycling of Sodium Nickel Chloride batteries
The SoNick is 100% recyclable with a recycle program already in place in Europe and the USA, which can easily be duplicated in Australia at the appropriate time.
The battery materials are recycled to produce stainless steel where the nickel and iron go into alloys, while the salt and ceramic are used for road beds.
One company, Inmetco has successfully recycled more than 20 tonnes of SoNick or Zebra cells. Firstly the management electronics (BMS) are removed then the battery is processed by adding them to a standard submerged arc smelting furnace to produce nickel containing remelt alloy used in the stainless steel industry. The ceramic and salt contained in the cells is collected and the slag is compatible with this process. This is then sold as a replacement for limestone used in road construction – nothing goes to landfill.
Also there is sufficient value in the recycling process to cover any transport costs back to a recycler which makes the recycling process at worst cost neutral which means no additional recycling cost should need to be added to the consumer.
Recycling of Lead acid batteries
Lead acid batteries are the most established and the most recyclable of all large battery chemistries. At the moment, in Australia 80 – 90% of traditional lead acid batteries are recycled. 5 – 10% are stored in homes and 10 – 15% are sent to landfill.
Used lead acid batteries (ULAB) are recyclable and have a commercial value. Close to 100% of the materials can be recycled and there is a well-established infrastructure for collection and recycling.
The newer sealed gel lead acid batteries often have their plates doped which affects their ability to be recycled.
Recycling of Lithium Ion batteries
Lithium ion (Li-ion) batteries are currently the major competitor to traditional lead acid batteries. There are over 50 variations of electrode chemistry that are currently in use or emerging. Some of the most common are Lithium nickel manganese cobalt oxide (also known as NMC), Lithium iron phosphate (also known as Li-ferrous, LFP or LiFePO4), Lithium manganese oxide (also known as Li manganese, LMO or Spinel), and Lithium titanate. These each have their own characteristics and recycling problems.
Recycling technologies for Li-ion are still being developed. A high recovery rate of materials is difficult due to varieties of chemical components and system complexity. Currently the majority of used lithium ion batteries, of any size, are exported for recycling. There is rarely clear information available on whether these exported lithium ion batteries are recycled safely of efficiently or just go to landfill in other countries.
Although theoretically lithium ion can be recycled at end of life of lithium ion batteries, most batteries only contain on average 3% lithium. Most of the value in a used Li-ion battery is from the cobalt, nickel and copper components. These metals are being reduced or removed in newer Li-ion batteries, and this reduces their value to recyclers. It is unlikely you will be able to recycle more than 10 to 15 percent of a lithium battery because by weight that’s about all the valuable metals that are in the battery, including any recyclable casings and electrics.
This means that there is little of economic value in lithium ion energy storage batteries to make recycling economic for recycling companies which means without heavy government funding it is unlikely to happen.
Other issues in the recycling process of lithium ion batteries is if they hold any charge at all they can explode which happens when they are inadvertently placed in a lead acid battery recycling process. Many lithium ion batteries are not clearly identified and may look like lead acid batteries. To avoid this lithium ion batteries are frozen with liquid nitrogen then shredded while frozen. This is an expensive process.
Lithium ion batteries in the waste recovery process or ending up in landfill are particularly problematic as if they get too hot they can catch fire and if they get wet they can explode. This causes a very real safety issue in landfill situations. Lithium is also toxic.
Although there are currently some lithium ion recycling processes in Australia they are only suitable for small watch or phone sized batteries not household energy storage batteries. Currently only around 2 – 3% of small lithium ion batteries are recycled.
There is expected to be strong growth in waste Li-ion batteries over the next 20 years. Waste Electric Vehicle and Grid Storage Lithium-ion batteries streams are projected to begin flowing through to waste infrastructure in significant amounts by around 2025.
If you would like to know more about getting safe, reliable, recyclable, SoNick (molten salt) battery storage for your own home, business or micro-grid application visit us at http://quantum.GridEdge.com.au