How to Recycle Batteries

How to Recycle Batteries

Articla from http://batteryuniversity.com

Lead acid led to the success of early recycling and today more than 97 percent of these batteries are recycled in the USA. The automotive industry should be given credit for having organized recycling early on.  The recycling process is simple and 70 percent of the battery’s weight is reusable lead. As a result, over 50 percent of the lead supply comes from recycled batteries. Other battery types are not being returned as readily as lead acid, and several organizations are working on programs to make collection of spent batteries more convenient. Only 20 to 40 percent of cellular phone and consumer batteries are currently recycled.

The main objective for recycling batteries is to prevent hazardous materials from entering landfills. Lead acid and nickel-cadmium batteries are of special concern, and although Li-ion is less harmful, the aim is to include all batteries in the recycling programs. Do not store old lead acid batteries in households where children play. Simply touching the lead poles can be harmful. 

Even though they are environmentally unfriendly, lead acid batteries continue to hold a strong market niche. Wheeled mobility and UPS systems could not run as economically if it were not for this reliable battery. NiCd also continues to hold a critical position among rechargeable batteries. Large flooded NiCds start the Auxiliary Power Unit (APU) of commercial airplanes and power sightseeing boats in rivers of larger cities, pollution-free.

Toxic batteries will continue to be with us for a while longer because we have no practical alternatives. There is nothing wrong in using these batteries as long as we properly dispose of them. Europe banned NiCds in consumer products because there is a suitable replacement, the NiMH battery. Controlling the disposal of NiCds from consumer products is difficult because many users do not know that the retiring equipment includes this battery. The long-term environmental damage if the world’s NiCds were improperly disposed of could be devastating.

Let’s look at what happens when NiCds are carelessly disposed of in landfills. The metallic cylinder of the cell eventually begins to corrode and the cadmium gradually dissolves, seeping into the water supply. Once such contamination begins, the authorities have few options to stop the carnage. Our oceans already show traces of cadmium (along with aspirin, penicillin and antidepressants) but scientists are not certain of its origin. Regulatory discipline will lead to a cleaner environment for the next generations.

Nickel-metal-hydride batteries contain nickel and electrolyte, which are considered semi-toxic. If no disposal service is available in an area, individual NiMH batteries can be discarded with other household waste. When accumulating 10 or more batteries, the user should consider disposing of the packs in a secure waste landfill. The better alternative is bringing the spent batteries to a neighborhood drop-off bin for recycling.

Primary lithium batteries contain metallic lithium that reacts violently when in contact with moisture and the batteries must be disposed of appropriately. If thrown in the landfill in a charged state, heavy equipment operating on top could crush the cases and the exposed lithium would cause a fire. Landfill fires are difficult to extinguish and can burn for years underground. Before recycling, apply a full discharge to consume the lithium content. Non-rechargeable lithium batteries are used in military combat, as well as watches, hearing aids and memory backup. Li-ion for cell phones and laptops do not contain metallic lithium.

In North America,Toxco and Rechargeable Battery Recycling Corporation (RBRC) collect spent batteries and recycle them. While Toxco has its own recycling facilities, RBRC is in charge of collecting batteries and sending them to recycling organizations. Toxco in Trail, British Columbia, claims to be the only company in the world that recycles large lithium batteries. They receive spent batteries from oil drilling in Nigeria, Indonesia and other places. Toxco also recycles retired lithium batteries from the Minuteman missile silos and tons of Li-ion from the war in Iraq. Other divisions at Toxco recycle nickel-cadmium, nickel-metal-hydride, lead, mercury, alkaline and more.

Europe and Asia are also active in recycling spent batteries. Among other recycling companies, Sony and Sumitomo Metal in Japan and Unicore in Belgium have developed technology to retrieve cobalt and other precious metals from spent lithium ion batteries. The raw material lithium can also be retrieved and re-used repeatedly.

 Recycling Process

Recycling begins by sorting the batteries into chemistries. Collection centers place lead acid, nickel-cadmium, nickel-metal-hydride and lithium‑ion into designated drums, sacks or boxes. Battery recyclers claim that if a steady stream of batteries, sorted by chemistry, were available at no charge, recycling would be profitable.

The recycling process generally begins by removing the combustible material, such as plastics and insulation, with a gas-fired thermal oxidizer. The plant’s scrubber eliminates the polluting particles created by a burning process before releasing them into the atmosphere. This leaves the clean and naked cells with their valuable metal content. The cells are then chopped into small pieces and heated until the metal liquefies. Non-metallic substances are burned off; leaving a black slag on top that a slag arm removes. The alloys settle according to weight and are skimmed off like cream from raw milk while in liquid form.

Cadmium is relatively light and vaporizes at high temperatures. In a process that appears like a pan of water boiling over, a fan blows the cadmium vapor into a large tube cooled with water mist, and the vapors condense to produce cadmium that is 99.95 percent pure.

Some recyclers do not separate the metals on site but pour the liquid metals directly into what the industry refers to as “pigs” (65 pounds, 24kg) or “hogs” (2,000 pounds, 746kg). Other battery recyclers use the 7-pound nuggets (3.17kg). The pigs, hogs and nuggets are then shipped to metal recovery plants where they are used to produce nickel, chromium and iron for stainless steel and other high-end products.

Toxco uses liquid nitrogen to freeze lithium-based batteries before shredding, crushing and removal of the lithium, as well as other battery components. The lithium is dissolved in a solution to make the metal non-reactive and is sold for producing lubricating greases. Similarly, the cobalt is separated, collected and sold.

Battery recycling is energy-intensive, and it takes 6 to 10 times more energy to reclaim metals from recycled batteries as it does to produce the materials through other means, including mining. Let’s explore who pays for the recycling of batteries.

Each country imposes their own rules and fees to make recycling feasible. In North America, some recycling plants invoice on weight, and the rates vary according to chemistry. Nickel-metal-hydride yields the best return, as recycling produces enough nickel to pay for the process. The highest recycling fees apply to nickel-cadmium and lithium‑ion, because the demand for cadmium is low and lithium‑ion contains little in retrievable metal.

Rather than calculate the cost according to battery chemistry, some countries deal in tonnage. The flat cost to recycle a ton of batteries is $1,000 to $2,000, and Europe hopes to achieve a cost per ton of $300. Ideally, this would include transportation, but moving and handling the goods is expected to double the overall cost. To simplify transportation, Europe is setting up several smaller processing plants in strategic geographic locations.

Manufacturers, agencies and governments still must provide subsidies to support the battery recycling programs. This is underwritten by a tax added to each manufactured cell. RBRC receives funding from such a program.

Battery Recycling as a Business

Lithium-ion batteries are expensive to manufacture and this is mainly due to the high raw material cost and complex preparation processes. The most costly metal of most Li-ion is cobalt, a hard lustrous gray material that’s also used to manufacture magnets and high-strength alloys.

The first commercial Li-ion battery of the early 1990s was lithium iron cobalt.  The high specific energy made this battery popular for mobile phones, laptops and digital cameras. Other lithium-ion systems soon emerged, in part to substitute cobalt with the lower-cost manganese and nickel, as well as to gain better load capability, improve safety and prolong service life. Then came lithium iron phosphate, a lithium-based battery that uses no cobalt. This system delivers excellent load capability and offers high stability, but comes at the cost of lower specific energy. See Types of Lithium-ion Batteries. Table 1 lists the material value per ton of lithium-ion batteries. The table also includes lead acid, the easiest and most profitable battery to recycle.

Battery Chemistry	Metal value (per ton)	Table 1: Metal value per ton of battery Lead acid remains the most suitable battery to recycle; 70% of its weight contains reusable lead.
Lithium cobalt oxide	$25,000
Lithium iron phosphate	$400
Lead acid	$1,500

Knowing that billions of Li-ion batteries are discarded every year, and given the high cost of cobalt, one wonders why so few companies recycle these batteries. The reason becomes clear when examining the complexity and low yield. The retrieved raw material barely pays for labor, which includes collection, transport, sorting into batteries chemistries, shredding, separation of metallic and non-metallic materials, neutralizing hazardous substances, smelting, and purifying the recovered metals. See How to Recycle Batteries.

Consumers return 20–40 percent of spent household batteries for recycling. Many are faded laptop batteries, their life if known to be short, but one of the highest numbers comes from mobile phones. Since the battery is the only replaceable part of most mobile phones, service providers replace them as a way to solve an apparent phone problem. Most times, the fault lies elsewhere and examining the returned batteries reveal that 90 percent of these returned packs are good or can be restored with a simple service.

Ingenious entrepreneurs have discovered a business opportunity to test and recirculate batteries that have been collected in overflowing boxes under the counters of mobile phone stores. Battery service centers have sprung up in the USA, UK and Israel. They purchase surplus batteries by the ton and check them with Cadex battery analyzers. This is made possible with QuickSort™, a technology that assesses the battery state-of-health in 30 seconds. Read more about Testing Lithium-based Batteries.

Some service centers handle as many as 400,000 batteries per month. Customers receiving restored B-Class batteries offer the same performance as new packs with no increased returns. Figure 2 shows a box of unwanted mobile phone batteries for testing and recirculation. Restoring discarded batteries offers a profitable and clean alternative to recycling.

Figure 2: Discarded mobile phone batteries for service and redistribution 90% of warranty returns can be serviced. Modern battery rapid-test technologies make rapid sorting possible. Courtesy of Cadex

Larger batteries can also be tested and reused. Several companies, including ABB, are studying the redeployment of reclaimed batteries from electric vehicles. EV batteries have a longer life than packs used in mobile phones and laptops. EV manufacturers estimate up to 70 percent remaining capacity after 10 years of service when the car may be worn out. This presents sufficient reserve performance for less demanding application such as residential and commercial energy storage systems. An effective rapid-test method to check these larger batteries does not yet exist and would help the business case.

Lead acid are the most widely recycled batteries and the automotive industry receives credit for making this possible early on. Recycling programs are believed to have started soon after Cadillac introduced the cranking motor in 1912. The process is simple and up to 70 percent of the battery’s weight yields reusable lead. In the USA, recycled batteries provide over 50 percent of the lead supply, and leading lead-acid battery manufacturers, including Johnson Controls and Exide Technologies, run profitable recycling operations. There are over 100 million e-bikes on Chinese roads and the mostly lead acid batteries are responsible for 20 percent of China’s 3.7 tons of lead refining. 

Recycling can be dirty and the EPA (Environmental Protection Agency) has imposed strict guidelines to recycle lead acid batteries. The plants must be sealed and the smokestacks fitted with scrubbers. To check for possible lead escape, the perimeters must be surrounded by lead-monitoring devices.

However, people find loopholes. Lead is gold and many batteries end up in Mexico and other developing countries with lax regulations. This puts workers and residents at risk of lead poisoning. Lead can enter the body by inhaling lead dust or ingestion by touching the mouth with lead-contaminated hands. Children are most vulnerable; excessive lead can affect growth, cause brain damage, harm kidneys, impair hearing and induce behavioral problems. Read more about Health Concerns with Batteries.

Nickel-based batteries can also be recycled and the retrieved materials are iron and nickel, materials used in stainless steel production. Nickel-metal-hydride (NiMH) yields the highest return in nickel and with enough supply, the recycling process is said to make money. The lower demand for cadmium has a reduced profitability for NiCd batteries. Furthermore the difficulty to retrieve precious metals from Li-ion makes this battery less attractive and a financial breakeven may not be possible. Although alkaline and carbon zinc amount to over 90 percent of batteries consumed in the United States, the precious metals content is low, so is the toxicity. Nevertheless, organizations are seeking ways to recycle them also. Table 3 lists the typical metals content of commonly recycles batteries.

	Fe Iron	Mn Manganese	Ni Nickel	Zn Zinc	Li Lithium	Cd Cadmium	Co Cobalt	Al Aluminum	Pb Lead
Lead acid									65
NiCd	35		22			15
NiMH	20	1	35	1			4
Li-ion	22				3		18	5
Alkaline	24	22		15

Table 3: Metals in commonly recycled batteries as a percentage of the overall content. The metal content may vary according to battery type.

Battery recycling is energy-intensive and it takes 6–10 times more energy to reclaim metals from recycled batteries than through other sources, including mining. Efficient logistics to get the batteries is important, and recyclers claim that the business could be profitable if a steady stream of batteries, sorted by chemistry, were available at no charge. See also How to Recycle Batteries.

Recycling Lithium

Some lobby groups warn about an imminent lithium shortage; they compare lithium to fossil oil as the future commodity of high demand. The need for Li-ion batteries is indeed increasing, and finding sufficient lithium as a raw material could be a challenge for the mining industry. A compact EV battery (Nissan Leaf) uses about 4kg (9lb) of lithium. If every man, woman and teenager were to drive an electric car, a lithium shortage could indeed develop.

Lithium is named after the Greek word “lithos” meaning “stone.” About 70 percent of the world’s supply comes from brine (salt lakes); the remainder is derived from hard rock. Scientists are developing technology to draw lithium from seawater. China is the largest consumer of lithium; they believe that future cars will run on Li-ion batteries and an unbridled supply of lithium is important to them. The total demand for lithium in 2009 reached almost 92,000 metric tons, of which batteries consumed 26 percent. Figure 4 illustrates uses of lithium that also include lubricants, glass, ceramics, pharmaceuticals and refrigeration.

Figure 4: Lithium consumption (2008) Batteries consume the highest percentage of lithium. With the advent of the electric vehicle, the demand could skyrocket but for now the world has enough proven reserve. Courtesy of Talison MineralsMost of the known lithium sources are in Bolivia, Argentina, Chile, Australia and China. The supply is ample and concerns of global shortages are speculative. It takes 750 tons of brine, the base of lithium, and 24 months of preparation to get one ton of lithium in Latin America. Lithium can also be recycled an unlimited number of times; 20 tons of spent Li-ion batteries yield one ton of lithium, but recycling could be more expensive than harvesting new supply through mining. The recycled lithium is contaminated and has a quality similar to raw material that needs much processing.

Lithium is inexpensive. The raw material costs a fraction of one cent per watt, or less than 0.1 percent of the battery cost. A $10,000 battery for a plug-in hybrid contains less than $100 worth of lithium. Rather than worrying about a lack of lithium, graphite, the anode material, could be in short supply. A large EV battery uses about 25kg (55lb) of anode material. The process to make anode-grade graphite with 99.99 percent purity is expensive and produces much waste.

There is also a concern about shortages of rare earth materials for permanent magnets. Electric motors with permanent magnets are among the most energy efficient and they are found in many EV powertrains. China controls about 95 percent of the global market for rare earth metals and they expect to use most of these resources for its own production. High prices of these metals may encourage more recycling in the future but current methods are difficult because the material tends to oxidize. Returning these elements to their metallic state requires special procedures that may not be economical with current technologies. 

Summary

Batteries are made for good performance and long life at a low price. Recycling is an afterthought and manufacturers invest little to simplify retrieving precious metals. The recycling business is small compared to the vast battery industry, and to this day only lead acid can be recycled profitably. Nickel-based batteries might make money with good logistics, but Li-ion and most other chemistries yield too little in precious metals to make recycling a viable business without subsidies. The true cost to manufacture a modern battery is not only in raw materials alone but in preparation, purification and processing into micro- and nano-structures. Recycling brings the metal to ground zero from which the preparations must start anew.

To make the recycling business feasible, subsidies are needed by adding a tax to each cell sold. Perhaps more important than earning a profit is preventing toxic batteries from entering landfills. Soil contamination can be harmful to health and is difficult to reverse.  

The key in reducing the battery wasteland, however, is to respect batteries by treating them well and only discard them when no salvage remedy exists. Better charge methods, clever battery monitoring systems (BMS) and advanced battery test devices help in getting the full life out of a battery. Too many batteries are being replaced as a way to troubleshoot an apparent problem. Advanced diagnostic devices help in eliminating trial-by-error so that only batteries with valid deficiencies are being exchanged.

Summary of Do’s and Don’ts

Table 1 provides suggestions on how to extend battery life by following simple guidelines. Because of similarities within systems, the chemistries are limited to lead, nickel and lithium.

Table 1: Dos and don’ts summary how to use, maintain and dispose of batteries.

Battery care	Lead acid: Flooded, sealed, AGM	Nickel-based: NiCd, NiMH	Lithium-ion: Cobalt, manganese, phosphate
Best way to charge	Apply a saturated charge to prevent sulfation; can stay on charge with correct float charge.	Avoid getting battery too hot on charge. Do not leave battery in charger for more than a few days (memory!).	Partial and random charge is fine; does not need full charge; lower voltage limit preferred; keep battery cool.
Charge methods	Constant voltage to 2.40–2.45/cell, float at 2.25–2.30V/cell; battery stays cool; no fast charge possible. Charge  = 14h	Constant current, trickle charge at 0.05C, fast charge preferred. Slow charge  = 14h Rapid charge = 3h Fast charge   = 1h	Constant voltage to 4.20V/cell; no trickle charge; battery can stay in charger Rapid charge = 3h Fast charge = 1h
Discharge	Do not cycle starter batteries; avoid full discharges; always charge after use.	Do not over-discharge under heavy load; cell reversal causes short. Avoid full discharges.	Prevent full cycles, apply some charge after a full discharge to keep the protection circuit alive.
How to prolong battery	Limit deep cycling, apply topping charge every 6 months while in storage to prevent sulfation, keep cells at or above 2.10V	Do not keep battery in charger for more than a few days, discharge to 1V/cell every 1–3 months to prevent memory (NiCd)	Keep cool, battery lasts longest when operating in mid state-of-charge of 20–80%. Prevent ultra-fast charging and high loads.
Storage	Do not store below 2.10V/cell; keep fully charged if possible	Store in cool place; NiCd stores for 5 years; prime before use	Store at 40% charge in cool place (40% SoC reads 3.75–3.80V/cell)
Disposal	Do not dispose. Lead is a toxic metal	NiCd: Do not dispose. NiMH: Can be disposed in low volume	Can be disposed of in low volume