Self-discharge

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Self-discharge is a phenomenon in batteries in which internal chemical reactions reduce the stored charge of the battery without any connection between the electrodes or any external circuit. [1] Self-discharge decreases the shelf life of batteries and causes them to have less than a full charge when actually put to use. [1]

Contents

How fast self-discharge in a battery occurs is dependent on the type of battery, state of charge, charging current, ambient temperature and other factors. [2] Primary batteries are not designed for recharging between manufacturing and use, and thus to be practical they must have much lower self-discharge rates than older types of secondary cells. Later, secondary cells with similar very low self-discharge rates were developed, like low-self-discharge nickel–metal hydride cells.

Self-discharge is a chemical reaction, just as closed-circuit discharge is, and tends to occur more quickly at higher temperatures. Storing batteries at lower temperatures thus reduces the rate of self-discharge and preserves the initial energy stored in the battery. Self-discharge is also thought to be reduced as a passivation layer develops on the electrodes over time.

Typical self-discharge by battery type

Battery chemistryRechargeableTypical self-discharge or shelf life
Lithium metal No10 years shelf life [3]
Alkaline No5 years shelf life [3]
Zinc–carbon No2–3 years shelf life [3]
Lithium-ion Yes2–3% per month; [3] ca. 4% p.m. [4]
Lithium-polymer Yes~5% per month [5] [ better source needed ]
Low self-discharge NiMH YesAs low as 0.25% per month [6]
Lead–acid Yes4–6% per month [3]
Nickel–cadmium Yes15–20% per month [3]
Conventional nickel–metal hydride (NiMH)Yes30% per month [3]

Related Research Articles

<span class="mw-page-title-main">Electrochemistry</span> Branch of chemistry

Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference and identifiable chemical change. These reactions involve electrons moving via an electronically-conducting phase between electrodes separated by an ionically conducting and electronically insulating electrolyte.

<span class="mw-page-title-main">Electrode</span> Electrical conductor used to make contact with nonmetallic parts of a circuit

An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit. Electrodes are essential parts of batteries that can consist of a variety of materials depending on the type of battery.

<span class="mw-page-title-main">Electrochemical cell</span> Electro-chemical device

An electrochemical cell is a device that generates electrical energy from chemical reactions. Electrical energy can also be applied to these cells to cause chemical reactions to occur. Electrochemical cells that generate an electric current are called voltaic or galvanic cells and those that generate chemical reactions, via electrolysis for example, are called electrolytic cells.

<span class="mw-page-title-main">Nickel–metal hydride battery</span> Type of rechargeable battery

A nickel–metal hydride battery is a type of rechargeable battery. The chemical reaction at the positive electrode is similar to that of the nickel-cadmium cell (NiCd), with both using nickel oxide hydroxide (NiOOH). However, the negative electrodes use a hydrogen-absorbing alloy instead of cadmium. NiMH batteries can have two to three times the capacity of NiCd batteries of the same size, with significantly higher energy density, although only about half that of lithium-ion batteries.

<span class="mw-page-title-main">Nickel–cadmium battery</span> Type of rechargeable battery

The nickel–cadmium battery is a type of rechargeable battery using nickel oxide hydroxide and metallic cadmium as electrodes. The abbreviation Ni–Cd is derived from the chemical symbols of nickel (Ni) and cadmium (Cd): the abbreviation NiCad is a registered trademark of SAFT Corporation, although this brand name is commonly used to describe all Ni–Cd batteries.

<span class="mw-page-title-main">Lithium-ion battery</span> Rechargeable battery type

A lithium-ion or Li-ion battery is a type of rechargeable battery that uses the reversible intercalation of Li+ ions into electronically conducting solids to store energy. In comparison with other rechargeable batteries, Li-ion batteries are characterized by higher specific energy, higher energy density, higher energy efficiency, a longer cycle life, and a longer calendar life. Also noteworthy is a dramatic improvement in lithium-ion battery properties after their market introduction in 1991: within the next 30 years, their volumetric energy density increased threefold while their cost dropped tenfold.

<span class="mw-page-title-main">Rechargeable battery</span> Type of electrical battery

A rechargeable battery, storage battery, or secondary cell, is a type of electrical battery which can be charged, discharged into a load, and recharged many times, as opposed to a disposable or primary battery, which is supplied fully charged and discarded after use. It is composed of one or more electrochemical cells. The term "accumulator" is used as it accumulates and stores energy through a reversible electrochemical reaction. Rechargeable batteries are produced in many different shapes and sizes, ranging from button cells to megawatt systems connected to stabilize an electrical distribution network. Several different combinations of electrode materials and electrolytes are used, including lead–acid, zinc–air, nickel–cadmium (NiCd), nickel–metal hydride (NiMH), lithium-ion (Li-ion), lithium iron phosphate (LiFePO4), and lithium-ion polymer.

<span class="mw-page-title-main">Lead–acid battery</span> Rechargeable battery type often used in motor vehicles

The lead–acid battery is a type of rechargeable battery first invented in 1859 by French physicist Gaston Planté. It is the first type of rechargeable battery ever created. Compared to modern rechargeable batteries, lead–acid batteries have relatively low energy density. Despite this, they are able to supply high surge currents. These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by starter motors. Lead–acid batteries suffer from relatively short cycle lifespan and overall lifespan, as well as slow or long charging time.

<span class="mw-page-title-main">Galvanic cell</span> Electrochemical device

A galvanic cell or voltaic cell, named after the scientists Luigi Galvani and Alessandro Volta, respectively, is an electrochemical cell in which an electric current is generated from spontaneous oxidation–reduction reactions. A common apparatus generally consists of two different metals, each immersed in separate beakers containing their respective metal ions in solution that are connected by a salt bridge or separated by a porous membrane.

A primary battery or primary cell is a battery that is designed to be used once and discarded, and not recharged with electricity and reused like a secondary cell. In general, the electrochemical reaction occurring in the cell is not reversible, rendering the cell unrechargeable. As a primary cell is used, chemical reactions in the battery use up the chemicals that generate the power; when they are gone, the battery stops producing electricity. In contrast, in a secondary cell, the reaction can be reversed by running a current into the cell with a battery charger to recharge it, regenerating the chemical reactants. Primary cells are made in a range of standard sizes to power small household appliances such as flashlights and portable radios.

<span class="mw-page-title-main">Zinc–air battery</span> High-electrical energy density storage device

Zinc–air batteries (non-rechargeable), and zinc–air fuel cells are metal–air batteries powered by oxidizing zinc with oxygen from the air. These batteries have high energy densities and are relatively inexpensive to produce. Sizes range from very small button cells for hearing aids, larger batteries used in film cameras that previously used mercury batteries, to very large batteries used for electric vehicle propulsion and grid-scale energy storage.

<span class="mw-page-title-main">Rechargeable alkaline battery</span>

A rechargeable alkaline battery, also known as alkaline rechargeable or rechargeable alkaline manganese (RAM), is a type of alkaline battery that is capable of recharging for repeated use. The formats include AAA, AA, C, D, and snap-on 9-volt batteries. Rechargeable alkaline batteries are manufactured fully charged and have the ability to hold their charge for years, longer than nickel-cadmium and nickel-metal hydride batteries, which self-discharge. Rechargeable alkaline batteries can have a high recharging efficiency and have less environmental impact than disposable cells.

<span class="mw-page-title-main">VRLA battery</span> Type of lead–acid battery

A valve regulated lead–acid (VRLA) battery, commonly known as a sealed lead–acid (SLA) battery, is a type of lead–acid battery characterized by a limited amount of electrolyte absorbed in a plate separator or formed into a gel; proportioning of the negative and positive plates so that oxygen recombination is facilitated within the cell; and the presence of a relief valve that retains the battery contents independent of the position of the cells.

A polymer-based battery uses organic materials instead of bulk metals to form a battery. Currently accepted metal-based batteries pose many challenges due to limited resources, negative environmental impact, and the approaching limit of progress. Redox active polymers are attractive options for electrodes in batteries due to their synthetic availability, high-capacity, flexibility, light weight, low cost, and low toxicity. Recent studies have explored how to increase efficiency and reduce challenges to push polymeric active materials further towards practicality in batteries. Many types of polymers are being explored, including conductive, non-conductive, and radical polymers. Batteries with a combination of electrodes are easier to test and compare to current metal-based batteries, however batteries with both a polymer cathode and anode are also a current research focus. Polymer-based batteries, including metal/polymer electrode combinations, should be distinguished from metal-polymer batteries, such as a lithium polymer battery, which most often involve a polymeric electrolyte, as opposed to polymeric active materials.

<span class="mw-page-title-main">ZEBRA battery</span>

The ZEBRA battery is a type of rechargeable molten salt battery based on commonly available and low-cost materials – primarily nickel metal, the sodium and chloride from conventional table salt, as well beta-alumina solid electrolyte. It is technically known as the sodium–nickel–chloride battery, and sometimes as a sodium–metal–halide battery. The common name comes from its development under the Zeolite Battery Research Africa (ZEBRA) project, started in South Africa in 1985.

<span class="mw-page-title-main">Nickel–hydrogen battery</span> Type of rechargeable battery

A nickel–hydrogen battery (NiH2 or Ni–H2) is a rechargeable electrochemical power source based on nickel and hydrogen. It differs from a nickel–metal hydride (NiMH) battery by the use of hydrogen in gaseous form, stored in a pressurized cell at up to 1200 psi (82.7 bar) pressure. The nickel–hydrogen battery was patented on February 25, 1971 by Alexandr Ilich Kloss and Boris Ioselevich Tsenter in the United States.

An aqueous battery is an electric battery that uses a water-based solution as an electrolyte. The aqueous batteries are known since 1860s, do not have the energy density and cycle life required by the grid storage and electric vehicles, but are considered safe, reliable and inexpensive in comparison with the lithium-ion ones. Until 2010s they also had an advantage in high-power applications, but this was overcome by developments in the Li-ion chemistry.

<span class="mw-page-title-main">Electric battery</span> Power source with electrochemical cells

An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell.

<span class="mw-page-title-main">Supercapacitor</span> High-capacity electrochemical capacitor

A supercapacitor (SC), also called an ultracapacitor, is a high-capacity capacitor, with a capacitance value much higher than solid-state capacitors but with lower voltage limits. It bridges the gap between electrolytic capacitors and rechargeable batteries. It typically stores 10 to 100 times more energy per unit volume or mass than electrolytic capacitors, can accept and deliver charge much faster than batteries, and tolerates many more charge and discharge cycles than rechargeable batteries.

This is a list of commercially-available battery types summarizing some of their characteristics for ready comparison.

References

  1. 1 2 Garche, Jurgen; Dyer, Chris K.; Moseley, Patrick T.; Ogumi, Zempachi; Rand, David A. J.; Scrosati, Bruno (2013). Encyclopedia of Electrochemical Power Sources. Newnes. p. 407. ISBN   978-0-444-52745-5.
  2. Moseley, Patrick T.; Garche, Jurgen (27 October 2014). Electrochemical Energy Storage for Renewable Sources and Grid Balancing. Newnes. pp. 440, 441. ISBN   9780444626103.
  3. 1 2 3 4 5 6 7 Battery performance characteristics, MPower UK, 23 February 2007. Information on self-discharge characteristics of battery types
  4. Umweltbundesamt: "BATTERIEN UND AKKUS" (3,65 MB PDF), October 2012; visited 2018-02-14
  5. "Lithium Polymer Battery Technology" (PDF). Retrieved 14 March 2016.
  6. Panasonic

Further reading