Batteries store electrical energy to power devices. They can be categorized based on their chemical compositions which affects their price, energy densities and other characteristics.
Alkaline batteries are the most commonly used kind. They are a great choice for handheld gadgets like digital watches and calculators, but also work well in larger devices such as flashlights and automatic hand sanitizer dispensers.
Primary Batteries
Primary batteries are single-use power sources that provide electrical energy until the battery is depleted. Also known as dry cells, they are not rechargeable and will only last until their internal voltage is too low to function. Between terminal voltage vs emf, terminal voltage is always lesser than the emf of the cell. They are available in a variety of sizes from AA to D and can be used with most devices including clocks, radios, toys, flashlights and more. The primary cell batteries come in different shapes and designs depending on the mechanical and electrical requirements of a specific application. They may be cylindrical, prismatic types or coin type and can be sealed by crimping or using a plastic insulator between the positive and negative cases.
The most common primary cell is alkaline which provides high specific energy, long shelf life and is leak proof even when depleted. It is also cost effective, environmentally friendly and can be carried on airplanes without special restrictions. Its only drawback is its low load current limiting it to light loads.
Other types of primary cells include zinc-carbon (also called carbon-zinc and the Leclanche battery), alkaline-manganese and lithium iron disulfide (Li-FeS2). The latter is a relatively newcomer to the family and offers improved performance compared with an alkaline battery. Its advantages are higher capacity, lower internal resistance and low self-discharge allowing up to 15 years of storage at ambient temperatures.
Rechargeable batteries are based on the same electrochemical principles as primary cells, with electrons passing from the positive electrode to the negative through an electrolyte. The primary difference is that the process of transferring electrons from one electrode to another is reversible in a rechargeable battery. The most well-known rechargeable battery is the nickel-cadmium battery (NiCd or NiCad battery), which uses metallic cadmium and nickel oxide hydroxide as electrodes. This type of battery has a good charge retention but falls victim to the dreaded memory effect whereby repeated recharging reduces its future capacity.
Secondary Batteries
A secondary battery is an electrochemical storage cell designed for more than one use. It converts chemical energy into electrical energy and stores it as a reserve until it is activated or charged.
When a battery is charged, the chemical reactions in its cells are reversed and electrons flow from the cathode to the anode through the separator. Upon discharging, the flow is opposite, and the battery releases stored electrons into a circuit.
Most of the time, we associate batteries with their ability to power our electronic gadgets. However, there are other uses for them that have made them essential for the advancement of human society. For example, they are used for power generation in case of power failure or in order to provide supplementary electricity for stand-alone devices such as laptops, smartphones, and other handheld devices.
Battery technology is continuously improving and there are several different types of batteries available on the market. Most of the battery types are classified by their chemistry, which dictates a number of important attributes such as cycle life, shelf life, and price.
The most popular type of rechargeable battery today is lithium ion. These are found in most portable electronic devices such as smartphones, tablets, and laptops. Moreover, they are considered vital for the development of electric vehicles, which are seen as an eco-friendly and efficient mode of transportation in the future.
The anode material of Li-ion batteries is mainly graphite or carbon-based materials, with many variants including milled mesophase pitch-based carbon fibers and non-graphitizable types like polyparaphenylene-based carbon heat-treated at low temperatures. This article focuses on correlations between microstructure, texture, and crystallinity of these anode carbon materials and their electrochemical performance in Li-ion batteries. It also explores the effects of manufacturing processes on the anode carbon morphology and properties.
Rechargeable Batteries
Battery technology is the basis for electric devices that are used in our daily lives. All batteries have two internal layers called electrodes with a positive and negative terminal that transports ions through an electrolyte. The ions flow through the cathode and anode, where a chemical reaction that converts the ions to electrical energy takes place. The electrons then exit via the negative terminal, where they power your device.
Rechargeable Batteries are a form of secondary battery that can be recharged and reused. These batteries can hold a charge for a longer period of time than primary or disposable batteries and are more cost-effective over the long term than replacing a battery after each use. These batteries can be found in a variety of electronic products such as toys, clocks, alarm systems and remote control items.
Nickel-metal hydride (NiMH) and lithium ion (Li-ion) batteries are the most common rechargeable batteries. These batteries offer higher energy density than disposable alkaline batteries and are better suited for high-drain devices like digital cameras. However, even with the increased capacity offered by these batteries, their life expectancy is reduced when they are used to power high-drain devices.
Conclusion
Batteries are also essential in medical instruments like ECG heart monitors, and for storing data on portable tools such as metal detectors or flashlights. In addition, battery technology is being employed to store energy for load leveling in the power grid and renewable energy generation such as storing solar photovoltaics during the day to be utilized at night.