Batteries may produce the following potential problems or hazards:
- pollute the water as the metals vaporize into the air when burned
- expose the environment to lead and acid
- contain strong corrosive acids may cause burns to eyes and skin.


The U.S. Congress passed the Mercury-Containing and Rechargeable Battery Management Act in 1996 to make it easier for rechargeable battery and product manufacturers to collect and recycle batteries. The act requires the following:
- batteries must be easily removable from consumer products, to make it easier to recover them for recycling battery
- labels must include the battery chemistry, and a phrase indicating that the user must recycle or dispose of the battery properly
- national uniformity in collection, storage, and transport of certain batteries
- phase out the use of certain mercury-containing batteries.

The environmental impact of toxic waste batteries

Batteries supply many of the devices that work with electricity, even cars, but after they have been consumed and discarded, they pose a danger to the environment.
Batteries are classified into: primary batteries (not rechargeable) and secondary batteries (rechargeable), the latter having a larger search.
Batteries contain toxic and dangerous metals, until recently, they were simply discarded.

Materials Management

As demand for batteries has grown over the years throughout the world, pollution risks increased and, therefore, also the recycling methods needed to be improved in a continuous manner.
Fraction of recycled material actually consists of 3 factors: fraction of sold batteries that are returned, recoverable fraction of material in each battery and fraction of material actually recovered.

Finally it arrives at an effective recovery of approximately 54% of the total weight of the battery, very rarely can a battery be completely recovered.
Batteries are no longer what they used to be, by using them they change both physically and chemically. Accordingly, the battery can not be reused directly, having a need for a special processing before being recycled and turned into a new battery, or to be used in other purposes.
Recycling batteries involves several distinct operations:
- collection of waste batteries
- sorting them according to content
- recovery of recyclable material
- cleaning of the recyclable material
- throwing the parts that can’t be recycled
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Recycling technologies

There are several methods of recycling batteries components. Metals are recovered by pyrometallurgy, which uses very high temperatures. Another method is the hydrometallurgical technology, which uses water extraction usually under ambient pressure and temperature, and electrometallurgy, which uses electricity. For example, lead is recovered by pyrometallurgy, as well as nickel and cadmium, which by heating to a certain temperature and various processes are refined and reused.

Batteries are not recycled entirety, but on separate components: electrodes, electrolyte, separators and case. Recycling is different for each component. Metal electrodes are mostly recycled and the metal case is recycled to a much greater extent than that of plastic.
Electrodes can be reused as agents, but in most cases are used for other purposes.
Lead is the material most reused, followed by cadmium and other materials.

Classification of batteries



Secondary batteries

Rechargeable batteries (secondary batteries) are designed to be used a long period of time, between 100 and 1000 charging cycles.
They can be recharged by applying electrical energy using a battery charger.
Secondary batteries are economical and more advantageous than the primary batteries, therefore, reducing the volume of discarded batteries.
National Electrical Manufacturers Association estimated that the U.S. demand for rechargeable batteries is growing two times faster than the demand for primary batteries.

Lead-acid battery

The lead-acid battery, was invented in 1859 by the French physicist Gaston Planté, being the oldest rechargeable battery.
Current attempts are made to develop alternatives to lead-acid battery, because of environmental concerns as a result of incorrect recycling of old batteries.
The recycling of lead acid battery is one of the most successful. In the United States 97% of all lead-acid batteries are recycled.

Lead can be recovered by separating the various materials which formed the battery using a metallurgical process or by a process in which the battery is taken as a whole and placed in an furnace where at the end of the process the material is recovered.

Alkaline rechargeable battery

The rechargeable alkaline battery has a term of validity that may take years, compared with Ni-Cd and Ni-MH batteries that have a validity of 90 days.
These batteries are environmentally friendly and they don’t use toxic metals and batteries are less discarded.
Rechargeable alkaline batteries can be reworked using thermal processes, including melting, to recover the metal.

Nickel-iron battery

Nickel-iron battery is a cell having cathode hydrides of nickel oxide (III), iron anode and electrolyte of potassium hydroxide.
This battery affects the ecosystem in a very small extent, since it doesn’t contain heavy metals.
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Nickel-cadmium battery

Nickel-cadmium battery is a type of rechargeable battery that uses nickel oxide and hydrides of nickel and cadmium as metal electrodes.
Ni-Cd battery contains cadmium, a toxic metal, so their use was prohibited unless their used in medicine, alarms, emergency lighting and portable power tools.
Cadmium can cause major environmental pollution when thrown or incinerated, this is why many countries collect and recycle old Ni-Cd batteries.
The Ni-Cd battery, through a heat process the cadmium and nickel is recovered for steel production.

Nickel-Hydride battery

Nickel-Hydride battery (NiMH) is a secondary battery that uses a electrochemical process, similar to the nickel hydrogen cell and uses a hydrogen absorbing alloy for the negative electrode instead of cadmium.
NiMH batteries have a minor impact on the ecosystem compared to Ni-Cd batteries, due to the absence of cadmium.
NiMH batteries are reproduced by separating the materials in the structure (plastic,
hydrogen, nickel), resulting a material containing high levels of nickel, used to manufacture stainless steel.

Lithium-ion battery

Lithium-ion battery is a rechargeable battery where the lithium-ion moves between the anode and cathode, moving from the anode to cathode when discharging and from the cathode to anode when charging.
Lithium-ion batteries are reproduced by pyrolysis aimed primarily for the recovery of the metal content.

Lithium-polymer battery

The lithium-polymer battery (Li-Pol, LiPo, LIP; PLI; LiP) is a secondary battery, where the electrode is an organic solvent, a lithium salt, in a composite of polymer such as the polyethylene oxide.
The LiPo batteries are discharged until they reach the voltage of 1 V per cell, they’re put in salt and left for 2 weeks, then they can be disposed without environmental harm.

Lithium-iron phosphate battery

Lithium-iron phosphate battery (LiFePO4) is a secondary battery, it’s a lithium-ion battery that uses LiFePO4 as a cathode material.
These batteries are nontoxic and don’t harm the ecosystem.

Battery recycling


Bibliography materialelor