At EWaste Africa, our customers ask us questions like: “Why are batteries considered hazardous?” or “Why are some batteries recyclable while others are not?” To understand this, it helps to start with the basics.
A battery is not a single entity; it’s actually a pack made up of multiple individual cells. These cells are connected together in either series or parallel, depending on whether the device needs higher voltage or more current. In larger battery packs, like those used in electric vehicles or backup systems, you’ll often find a Battery Management System (or BMS), which ensures the cells are balanced, protected from overcharging or deep discharging, and functioning optimally.
A cell, on the other hand, is the building block of a battery. Each cell functions like a small chemical reactor, where a chemical reaction creates a flow of electrons, which is electricity. Electrons flow from the anode (through the negative terminal) to the cathode (through the positive terminal), and this flow powers our devices. In rechargeable batteries, this process can be reversed by applying electricity, effectively resetting the cell’s chemical state. The electrodes (anode and cathode) are suspended in a conductive electrolyte and separated by a separator, which allows ions to move while preventing the electrodes from touching and short-circuiting.
Cells come in various formats (cylindrical, pouch, and prismatic), depending on how the internal components are arranged. But what really sets them apart is their chemistry, which determines how much energy they can store, how safe they are, and how easy (or difficult) they are to recycle.
Here’s a breakdown of some common cell chemistries:
Alkaline cells commonly contain zinc and manganese dioxide. These cells are not rechargeable but are inexpensive to manufacture and can be easily recycled. Those are the most common non-rechargeable cells you can buy and are used to power your remotes, gamepads and toys. If these are damaged, they can spill corrosive electrolytes. The result of this corrosion is often seen as a white powder on the outside of your old alkaline cells.
Lead acid cells contain lead and sulphuric acid, making them hazardous if not properly managed at end-of-life. However, in South Africa, more than 95% of lead-acid batteries are recycled due to a well-established take-back system. They are extremely safe to operate but are not suitable for repeated cycling, such as home battery energy storage systems (BESS). They require slow charging and discharging to prevent damage. This kind of battery is most commonly used in your internal combustion engine car.
Nickel cadmium (NiCd) cells contain nickel and cadmium – a toxic element that must be kept out of the environment. These cells have medium energy density and can operate across a wide temperature range, making them useful in demanding conditions where other chemistries cannot be operated safely.
Nickel metal hydride (NiMH) cells use nickel and rare earth metals. They offer medium energy density and good safety characteristics. As the NiCd batteries contain toxic cadmium, this chemistry was meant to replace them for the public market. However, NiMH batteries are being phased out in favour of lithium-ion cells because they are heavier and cost more than lithium-ion cells.
Lithium-ion batteries are a broad category, with multiple chemistries tailored to different applications. All lithium-ion chemistries are hazardous to one degree or another due to the risk of spontaneous combustion and thermal runaway (leading to fires or explosions), especially when the cells are damaged or stored for long periods of time. This makes careful handling, storage, and recycling of lithium-ion batteries absolutely essential.
- Lithium-cobalt-oxide (LCO) cells offer the highest energy density, making them ideal for lightweight, high-value electronics. However, they pose fire risks if damaged and use expensive cobalt, which has a complex supply chain (including risks of inadvertently supporting child labour and unsafe work conditions).
- Lithium manganese oxide (LMO) cells are safer and cheaper due to the use of manganese. They have lower energy density but higher discharge rates. Previously used in hybrid vehicles and laptops, they’ve largely been replaced by LFP cells, which are even cheaper.
- Nickel-manganese-cobalt (NMC) cells come in several ratios (e.g., NMC111, NMC811 where the number corresponds with the ratio of each element) and provide a balance of energy density, safety, and long life. They are preferred for many mid-range applications, including power tools and appliances.
- Lithium iron phosphate (LFP) cells are the most cost-effective and among the safest lithium-ion options. While they have lower energy density and volumetric capacity, their affordability is driving wider adoption, especially in applications where cost is more critical than size or weight.
- Lithium manganese iron phosphate (LMFP) cells are a new chemistry being developed. This chemistry blends many of the advantages of NMC cells with the reduced cost and safety of LFP cells.
Sodium-ion cells are another new chemistry which have the advantages of lower costs than lithium cells and greatly improved safety features. Unfortunately, their energy density is currently lower than that of lithium-ion cells, making them best suited to stationary applications such as BESS.
At EWaste Africa, we specialise in the end-of-life management of almost all battery types. Whether this is through reuse (extending the life of viable cells) or through environmentally responsible recycling that recovers valuable materials, we ensure that batteries are dealt with safely and sustainably. With battery use continuing to rise across all sectors, the way we handle these powerful chemical packages at end-of-life has never been more important, especially given that all batteries are banned from being disposed of into landfill, regardless of the chemistry.
If you’re unsure how to dispose of your batteries or want to partner with a responsible recycler, we’re here to help.
Let’s power a cleaner future—together.
