Types of Battery

Different types of batteries use different electrode materials, electrolytes, cell formats and control systems. A battery supplies electrical energy through electrochemical reactions and may contain one cell or several connected cells. Primary batteries are designed for one discharge life. Secondary batteries are designed to be recharged under specified conditions. Neither class is always cheaper, safer, longer-lived or more powerful: selection depends on voltage, capacity, power, temperature, storage life, cycle life, size and the device’s protection requirements.
Standard designations help identify a cell’s electrochemical system and dimensions. A marking such as AA LR6 1.5 V combines a common size name, an IEC designation and nominal voltage. It does not by itself describe capacity or suitability for a particular load.

The example is marked AA LR6 1.5 V. Each part has a different purpose:

• In the IEC primary-battery designation LR6, L identifies the alkaline zinc-manganese dioxide (MnO₂) electrochemical system, R identifies a round cell and 6 identifies the standard dimensional category. The R6/LR6 format has a maximum diameter of 14.5 mm and a maximum height of 50.5 mm.
• AA is the familiar common designation for this format. The chemistry still matters: R6, LR6 and FR6 cells can share the basic size while using zinc-carbon, alkaline or lithium iron-disulfide systems.

Consider the CR2025 coin cell shown below.

In the IEC designation CR2025, C identifies a lithium-manganese dioxide primary system and R identifies a round cell. The digits indicate a nominal 20 mm diameter and 2.5 mm height. Users must still follow the maker’s data and keep coin cells away from children because ingestion can cause severe internal injury.

Types of Battery

Primary Cells or Primary Batteries

Primary cells are not designed to be recharged. They include cylindrical, coin, button, flat and prismatic formats, but their power capability, storage life, leakage risk and usable temperature range depend on chemistry and construction. Typical uses include clocks, remote controls, sensors, smoke alarms, watches and medical devices. A primary cell must be replaced and disposed of or recycled according to its label and local rules.
A dry cell is not literally free of liquid. The term describes a cell whose electrolyte is immobilised as a paste, gel or absorbed phase rather than a freely flowing liquid. The figure shows a zinc-carbon dry cell.

Some common types of primary batteries and their main characteristics are described below.

Zinc-Carbon/Alkaline/MnO₂ Cell or Battery

Zinc-carbon and alkaline zinc-manganese dioxide are separate primary systems that both use manganese dioxide as the positive active material. Zinc-carbon cells use an acidic salt electrolyte and are suited to many low-drain products. Alkaline cells use an alkaline electrolyte and generally provide more capacity and better high-drain performance in the same format. Actual service depends on load, temperature, cutoff voltage and storage conditions.

Mercuric Oxide Batteries

Mercuric oxide cells use a zinc or cadmium negative electrode and a mercuric oxide positive electrode. Their stable voltage once suited specialised instruments, but mercury toxicity has led to strict restrictions and collection requirements. In the United States, mercuric oxide button cells are prohibited, while permitted larger products are limited to specialised military or medical uses with manufacturer collection systems. Availability and disposal rules vary by country, so these are not ordinary consumer replacements.

Zinc Silver Oxide Batteries

Silver oxide-zinc cells provide a relatively flat discharge voltage and are widely made in miniature button formats. Uses include watches, calculators and instruments where small size and stable voltage justify their material cost. Device compatibility requires matching voltage, dimensions, drain profile and manufacturer instructions.

Zinc Air Batteries

Zinc-air cells use oxygen from the surrounding air as a cathode reactant, leaving more internal volume for zinc and enabling high energy density. A sealed cell can have good storage life before activation. Removing the air-tab starts operation and also exposes the cell to humidity, carbon dioxide and drying, which limits useful life after activation. Common applications include hearing aids and other low-power devices designed for the required airflow.

Lithium Batteries

Primary lithium batteries are a family of non-rechargeable chemistries, including lithium-manganese dioxide coin cells and lithium iron-disulfide cylindrical cells. Many offer high specific energy and low self-discharge. Some also work over a wide temperature range, but ratings vary by chemistry and format. They must not be confused with rechargeable lithium-ion cells or placed in an unsuitable charger. Short circuit, reverse installation, mixing unlike cells, heat and ingestion of coin cells can create serious hazards.

Secondary Batteries

Secondary batteries use reactions designed to be reversed by a compatible charging system. Rechargeability is not unlimited: capacity and resistance change with age, temperature, storage state, charge rate and depth of discharge. Secondary batteries serve portable electronics, vehicles, uninterruptible power supplies, industrial equipment and stationary energy storage.
Each chemistry needs its specified charger, protection and operating limits. A charger intended for one battery chemistry or pack must not be assumed safe for another.

Lead Acid Batteries

Lead-acid batteries remain important for engine starting, standby power, traction and some renewable-energy systems. They can deliver high power at relatively low cost and have established recycling routes, but they are heavy for their stored energy and contain lead and corrosive sulfuric acid. Charging can generate hydrogen, so installation, ventilation, spill control and charging requirements must follow the product and applicable standards. A changing worldwide sales percentage should not be used as a timeless technical property.

Starting Batteries

Starting, lighting and ignition batteries are built to deliver high current for a short engine-cranking event and then be recharged. Repeated deep cycling can cause early damage. Applications include road vehicles, marine engines, aircraft and generator sets, with construction selected for the required cranking duty and environment.

Deep Cycle Batteries

Deep-cycle lead-acid batteries use plate and separator designs intended for repeated, substantial discharge. The permitted depth of discharge is product-specific; “80% before recharging” is not a universal operating target and deeper cycling often shortens life. Construction may be flooded, gelled-electrolyte or absorbed glass mat (AGM). Applications include industrial trucks, mobility equipment, golf carts and off-grid storage.

Submarine Batteries

Large submarine batteries are specialised propulsion and hotel-load systems designed around a vessel’s duty cycle, ventilation, shock requirements and maintenance regime. Their allowed discharge is set by the battery and vessel design; a universal 50% value does not describe every submarine installation.

Stationary Batteries

Stationary lead-acid systems provide standby or cycling service in telecommunications, substations, uninterruptible power supplies and renewable-energy installations. Their enclosure, ventilation, protection and maintenance depend on whether the cells are flooded or valve-regulated and on the site’s fault and autonomy requirements.

Nickel/Cadmium(Ni-Cd) Batteries

Nickel-cadmium batteries can provide long cycle life and high-rate capability. Their wide operating-temperature range supports some aviation, railway, emergency and industrial duties. Cadmium is toxic, so sale, collection and recycling are regulated in many places. Ni-Cd packs require a matching charge method and must not be discarded as ordinary waste.

Nickel Metal Hydride (NiMH) Batteries

Nickel-metal hydride cells avoid cadmium and can offer more capacity than a comparable Ni-Cd cell, but the result depends on cell size and design. NiMH has been widely used in consumer rechargeable cells and hybrid vehicles. Its challenges include heat during charging, self-discharge and charge-control requirements; it should not be ranked as universally “close” to lithium-ion without a defined metric.

Lithium-Ion Batteries

Lithium-ion is a family of rechargeable chemistries used in phones, laptops, power tools, electric vehicles and stationary storage. Its high energy per unit mass and volume supports portable and vehicle applications, but cost, power, cycle life and thermal behaviour vary with cell chemistry and pack design. Safe operation depends on cell qualification, mechanical protection, temperature monitoring, a compatible charger and a battery-management system that keeps voltage and current within specified limits.

Reserve Batteries

A reserve battery stores a necessary reactant or electrolyte separately so the cell remains inactive until commanded to activate. This can give long storage life for equipment that must work after years of standby. Activation may use water, heat, released electrolyte or gas. Reserve systems are common in military, aerospace and emergency equipment, but their power, run time and activation delay depend on the design; they are not all limited to short, high-power pulses.

Fuel Cell

A fuel cell is an electrochemical energy-conversion device, but it is not a battery type in the primary-versus-secondary classification. It produces electricity and heat while fuel and oxidant are supplied from outside. In a hydrogen fuel cell, hydrogen is fed to the anode and air or oxygen to the cathode. The electrode materials provide reaction sites and catalysts; the fuel itself is not the anode material. Fuel cells can power vehicles, buildings, backup systems and portable equipment, with scale and suitability set by the complete fuel-cell system. They are commonly classified by electrolyte:

1. Phosphoric Acid Fuel Cells.
2. Alkaline Fuel Cells.
3. Molten Carbonate Fuel Cells.
4. Proton Exchange Membrane Fuel Cells.
5. Solid Oxide Fuel Cells.