{"history":[],"article":{"id":"92a6ed0b-d3e6-475c-8ec7-4d4157a1de6b","title":"Lithium–sulfur battery","slug":"lithium-sulfur-battery","content":":::summary\n![Working principle of lithium-sulfur battery and \"shuttle\" effect](https://upload.wikimedia.org/wikipedia/commons/6/69/Li-S///battery///EN.png)\n**Etow:** 450 Wh/kg \n**Etos:** 550 Wh/L \n**Ctode:** C/5 nominal \n**Nomv:** Cell [voltage](https://bliptext.com/articles/volt) varies nonlinearly in the range 2.5–1.7V during discharge; batteries often packaged for 3V \n**Cd:** In question \n:::\n\n# \nThe **lithium–sulfur battery** (Li–S battery) is a type of [rechargeable battery](https://bliptext.com/articles/rechargeable-battery).\nIt is notable for its high [specific energy](https://bliptext.com/articles/specific-energy).\nThe low [atomic weight](https://bliptext.com/articles/atomic-weight) of [lithium](https://bliptext.com/articles/lithium) and moderate [atomic weight](https://bliptext.com/articles/atomic-weight) of [sulfur](https://bliptext.com/articles/sulfur) means that Li–S batteries are relatively light (about the density of water).\nThey were used on the longest and highest-altitude unmanned [solar-powered](https://bliptext.com/articles/solar-powered) aeroplane flight (at the time) by [Zephyr 6](https://bliptext.com/articles/airbus-zephyr) in August 2008.\nLithium–sulfur batteries may displace [lithium-ion](https://bliptext.com/articles/lithium-ion) cells because of their higher energy density and reduced cost.\nThis is due to two factors.\nFirst the use of [sulfur](https://bliptext.com/articles/sulfur) instead of a less energy dense and more expensive substances such as cobalt and/or iron compounds found in [lithium-ion batteries](https://bliptext.com/articles/lithium-ion-battery).\nSecondly, the use of metallic lithium instead of intercalating lithium ions allows for much higher energy density, as less substances are needed to hold \"lithium\" and lithium is directly oxidized.\nLi–S batteries offer specific energies on the order of 550[Wh](https://bliptext.com/articles/watt-hour)/[kg](https://bliptext.com/articles/kilogram), while lithium-ion batteries are in the range of 150–260[Wh](https://bliptext.com/articles/watt-hour)/[kg](https://bliptext.com/articles/kilogram).\nLi–S batteries with up to 1,500 charge and discharge cycles were demonstrated in 2017, but cycle life tests at commercial scale and with lean electrolyte have not been completed.\nAs of early 2021, none were commercially available.\nIssues that have slowed acceptance include the polysulfide \"shuttle\" effect that is responsible for the progressive leakage of active material from the cathode, resulting in too few recharge cycles.\nAlso, sulfur cathodes have low conductivity, requiring extra mass for a conducting agent in order to exploit the contribution of active mass to the capacity.\nVolume expansion of the sulfur cathode during S to Li2S conversion and the large amount of electrolyte needed are also issues.\nIn the early 2000s, however, scientists began to make progress creating high-stability sulfurized-carbon cathodes and by 2020, scientists at Rice University had demonstrated batteries based on sulfurized carbon cathodes that retained >70% of their capacity after 1000 cycles.\nBy 2023, [Zeta Energy](https://bliptext.com/articles/zeta-energy) a Texas-based startup announced that multiple national laboratories had independently verified that its lithium-sulfur batteries based on sulfurized-carbon cathodes were polysulfide shuttle free.\nThe competitive advantages of sulfurized-carbon cathodes (e.g., sulfurized polyacrylonitrile, also known as SPAN) were highlighted by a quantitative analysis performed by researchers at [University of Maryland, College Park](https://bliptext.com/articles/university-of-maryland-college-park) and [Pacific Northwest National Laboratory](https://bliptext.com/articles/pacific-northwest-national-laboratory) in 2024.\nTheir polysulfide shuttle free feature facilitates proper operation under lean electrolyte conditions (< 3 g·(A·h)−1), which was proved to be extremely crucial to attain the full potential of Li-S batteries.\nThe researchers proposed and analyzed unconventional perspectives on how to further improve both energy density and cycle life, highlighting the importance of a proper electrolyte (i.e., stable, lightweight, and highly Li+-conductive).\n\n# History\nLi–S batteries were invented in the 1960s, when Herbert and Ulam patented a primary battery employing lithium or lithium alloys as anodic material, sulfur as cathodic material and an electrolyte composed of [aliphatic](https://bliptext.com/articles/aliphatic-compounds) saturated [amines](https://bliptext.com/articles/amines).\nA few years later the technology was improved by the introduction of organic solvents as [PC](https://bliptext.com/articles/propylene-carbonate), [DMSO](https://bliptext.com/articles/dimethyl-sulfoxide) and [DMF](https://bliptext.com/articles/dimethylformamide) yielding a 2.35–2.5 V battery.\nBy the end of the 1980s a rechargeable Li–S battery was demonstrated employing ethers, in particular [DOL](https://bliptext.com/articles/dioxolane), as the electrolyte solvent.\nIn 2020 [Manthiram](https://bliptext.com/articles/arumugam-manthiram) identified the critical parameters needed for achieving commercial acceptance.\nSpecifically, Li–S batteries need to achieve a sulfur loading of >5 mg·cm−2, a carbon content of <5%, electrolyte-to-sulfur ratio of <5 μL·mg−1, electrolyte-to-capacity ratio of <5 μL·(mA·h)−1, and negative-to-positive capacity ratio of <5 in pouch-type cells.\nIn 2021, researchers announced the use of a sugar-based anode additive that prevented the release of polysulfide chains from the cathodes that pollute the anode.\nA prototype cell demonstrated 1,000 charge cycles with a capacity of 700 mAh/g.\nIn 2022, an interlayer was introduced that claimed to reduce polysulfide movement (protecting the anode) and facilitate lithium ion transfer to reduce charge/discharge times.\nAlso that year, researchers employed aramid nanofibers (nanoscale [Kevlar](https://bliptext.com/articles/kevlar) fibers), fashioned into cell membrane-like networks.\nThis prevented dendrite formation.\nIt addressed polysulfide shuttle by using ion selectivity, by integrating tiny channels into the network and adding an electrical charge.\nAlso in 2022, Researchers at [Drexel University](https://bliptext.com/articles/drexel-university) produced a prototype lithium-sulfur battery that did not degrade over 4000 charge cycles.\nAnalysis has shown that the battery contained monoclinic gamma-phase sulfur, which has been thought to be unstable below 95 degrees Celsius, and only a few studies have shown this type of sulfur to be stable longer than 20 to 30 minutes.\nIn 2024, researchers at [UC San Diego](https://bliptext.com/articles/university-of-california-san-diego) announced the discovery of a novel sulfur–iodine crystalline material that can drastically increase the electrical conductivity of a lithium–sulfur battery’s cathode by 11 orders of magnitude, making it 100 billion times more conductive than crystals made of sulfur alone.\nMoreover, the new material has self-healing properties which make it possible to repair the damage caused from recharge cycling by heating the new material.\n\n# Chemistry\nChemical processes in the Li–S cell include lithium dissolution from the [anode](https://bliptext.com/articles/anode) surface (and incorporation into [alkali metal](https://bliptext.com/articles/alkali-metal) [polysulfide](https://bliptext.com/articles/polysulfide) [salts](https://bliptext.com/articles/salt-chemistry)) during discharge, and reverse lithium [plating](https://bliptext.com/articles/electroplating) to the [anode](https://bliptext.com/articles/anode) while charging.\n\n## Anode\nAt the [anodic](https://bliptext.com/articles/anode) surface, dissolution of the metallic lithium occurs, with the production of electrons and lithium ions during the discharge and electrodeposition during the charge.\nThe [half-reaction](https://bliptext.com/articles/half-reaction) is expressed as:\nIn analogy with lithium batteries, the dissolution / electrodeposition reaction causes over time problems of unstable growth of the solid-electrolyte interface (SEI), generating active sites for the [nucleation](https://bliptext.com/articles/nucleation) and dendritic growth of lithium.\nDendritic growth is responsible for the internal short circuit in lithium batteries and leads to the death of the battery itself.\n\n## Cathode\nIn Li–S batteries, energy is stored in the sulfur [cathode](https://bliptext.com/articles/cathode) (S8).\nDuring discharge, the lithium ions in the electrolyte migrate to the cathode where the sulfur is reduced to [lithium sulphide (Li2S)](https://bliptext.com/articles/lithium-sulphide).\nThe sulfur is reoxidized to S8 during the recharge phase.\nThe semi-reaction is therefore expressed as:\nActually the sulfur reduction reaction to lithium sulphide is much more complex and involves the formation of lithium polysulphides (Li2Sx, 2 ≤ x ≤ 8) at decreasing chain length according to:\nOver all:\nAnd the final step:\nThe final product is actually a mixture of Li2S2 and Li2S rather than pure Li2S, due to the slow reduction kinetics at Li2S.\nThis contrasts with conventional lithium-ion cells, where the lithium ions are [intercalated](https://bliptext.com/articles/intercalation-chemistry) in the anode and cathodes.\nEach sulfur atom can host two lithium ions.\nTypically, lithium-ion batteries accommodate only 0.5–0.7 lithium ions per host atom.\nConsequently, Li–S allows for a much higher lithium storage density.\nPolysulfides are [reduced](https://bliptext.com/articles/redox) on the cathode surface in sequence while the cell is discharging:\nAcross a porous diffusion separator, sulfur [polymers](https://bliptext.com/articles/polymers) form at the [cathode](https://bliptext.com/articles/cathode) as the cell charges:\nThese reactions are analogous to those in the [sodium–sulfur battery](https://bliptext.com/articles/sodium-sulfur-battery).\nThe main challenges of Li–S batteries is the low conductivity of sulfur and its considerable volume change upon discharging and finding a suitable cathode is the first step for commercialization of Li–S batteries.\nTherefore, most researchers use a carbon/sulfur cathode and a lithium anode.\n[S](https://bliptext.com/articles/siemens-unit)ulfur is very cheap, but has practically no [electroconductivity](https://bliptext.com/articles/electric-conductance), 5[S](https://bliptext.com/articles/siemens-unit)⋅cm−1 at 25°C.\nA carbon coating provides the missing electroconductivity.\nCarbon nanofibers provide an effective electron conduction path and structural integrity, at the disadvantage of higher cost.\nIn 2024, researchers announced the discovery of a sulfur–iodine material that can dramatically increase the electrical conductivity of a lithium–sulfur battery’s cathode by 11 orders of magnitude, making it 100 billion times more conductive than crystals made of sulfur alone.\nOne problem with the lithium–sulfur design is that when the sulfur in the cathode absorbs lithium, volume expansion of the LixS compositions occurs, and predicted volume expansion of Li2S is nearly 80% of the volume of the original sulfur.\nThis causes large mechanical stresses on the cathode, which is a major cause of rapid degradation.\nThis process reduces the contact between the carbon and the sulfur, and prevents the flow of lithium ions to the carbon surface.\nMechanical properties of the lithiated sulfur compounds are strongly contingent on the lithium content, and with increasing lithium content, the strength of lithiated sulfur compounds improves, although this increment is not linear with lithiation.\nOne of the primary shortfalls of most Li–S cells is unwanted reactions with the electrolytes.\nWhile S and are relatively insoluble in most electrolytes, many intermediate polysulfides are not.\nDissolving into electrolytes causes irreversible loss of active sulfur.\nUse of highly reactive lithium as a negative electrode causes dissociation of most of the commonly used other type electrolytes.\nUse of a protective layer in the anode surface has been studied to improve cell safety, i.e., using [Teflon](https://bliptext.com/articles/teflon) coating showed improvement in the electrolyte stability, LIPON, Li3N also exhibited promising performance.\n\n# Polysulfide \"shuttle\" \nHistorically, the \"shuttle\" effect is the main cause of degradation in a Li–S battery.\nThe lithium polysulfide Li2Sx (6≤x≤8) is highly soluble in the common electrolytes used for Li–S batteries.\nThey are formed and leaked from the cathode and they diffuse to the anode, where they are reduced to short-chain polysulfides and diffuse back to the cathode where long-chain polysulfides are formed again.\nThis process results in the continuous leakage of active material from the cathode, lithium corrosion, low coulombic efficiency and low battery life.\nMoreover, the \"shuttle\" effect is responsible for the characteristic self-discharge of Li–S batteries, because of slow dissolution of polysulfide, which occurs also in rest state.\nThe \"shuttle\" effect in a Li–S battery can be quantified by a factor fc (0 < fc < 1), evaluated by the extension of the charge voltage plateau.\nThe factor fc is given by the expression:\nwhere ks, qup, [Stot] and Ic are respectively the kinetic constant, specific capacity contributing to the anodic plateau, the total sulfur concentration and charge current.\nIn 2022, researchers reported the use of a cathode made from [carbon nanofibers](https://bliptext.com/articles/carbon-nanofibers).\nElemental sulfur was deposited onto the carbon substrate (cf. [physical vapor deposition](https://bliptext.com/articles/physical-vapor-deposition)), which formed the rare and usually metastable monoclinic [γ-Sulfur](https://bliptext.com/articles/allotropes-of-sulfur) allotrope.\nThis allotrope reversibly reacts to without the formation of intermediate polysulfides.\nTherefore, carbonate electrolytes, which commonly react with those polysulfides, can be used instead of the rather dangerous ether based electrolytes (low flash and boiling points).\nIts initial capacity was 800 Ah/kg (classical LiCoO2/graphite batteries have a cell capacity of 100 Ah/kg).\nIt decayed only very slowly, on average 0.04% each cycle, and retained 658 Ah/kg after 4000 cycles (82%).\n\n# Electrolyte\nConventionally, Li–S batteries employ a liquid organic electrolyte, contained in the pores of PP separator.\nThe electrolyte plays a key role in Li–S batteries, acting both on \"shuttle\" effect by the polysulfide dissolution and the SEI stabilization at anode surface.\nIt has been demonstrated that the electrolytes based on organic carbonates commonly employed in Li-ion batteries (i.e. PC, [EC](https://bliptext.com/articles/ethylene-carbonate), D[EC](https://bliptext.com/articles/ethylene-carbonate) and mixtures of them) are not compatible with the chemistry of Li–S batteries.\nLong-chain polysulfides undergo nucleophilic attack on electrophilic sites of carbonates, resulting in the irreversible formation of by-products as [ethanol](https://bliptext.com/articles/ethanol), m[ethanol](https://bliptext.com/articles/ethanol), [ethylene glycol](https://bliptext.com/articles/ethylene-glycol) and [thiocarbonates](https://bliptext.com/articles/thiocarbonate).\nIn Li–S batteries are conventionally employed cyclic ethers (as [DOL](https://bliptext.com/articles/dioxolane)) or short-chain ethers (as [DME](https://bliptext.com/articles/dimethyl-ether)) as well as the family of glycol ethers, including DEG[DME](https://bliptext.com/articles/dimethyl-ether) and TEG[DME](https://bliptext.com/articles/dimethyl-ether).\nOne common electrolyte is 1M [LiTFSI](https://bliptext.com/articles/lithium-bis-trifluoromethanesulfonyl-imide) in DOL:DME 1:1 vol. with 1%w/w di LiNO3 as additive for lithium surface passivation.\n\n# Safety\nBecause of the high potential energy density and the nonlinear discharge and charging response of the cell, a [microcontroller](https://bliptext.com/articles/microcontroller) and other safety circuitry is sometimes used along with [voltage regulators](https://bliptext.com/articles/voltage-regulator) to manage cell operation and [prevent rapid discharge](https://bliptext.com/articles/thermal-runaway).\n\n# Lifespan\nLithium-sulfur (Li-S) batteries have a shorter lifespan compared to traditional [Li-ion batteries](https://bliptext.com/articles/li-ion-batteries).\nRecent advancements in materials and [electrolyte](https://bliptext.com/articles/electrolyte) formulations have shown potential to extend its [cycle life](https://bliptext.com/articles/cycle-life) to over 1,000 cycles.\nOne of the primary factors limiting the lifespan of Li-S batteries is the dissolution of [polysulfides](https://bliptext.com/articles/polysulfides) in the [electrolyte](https://bliptext.com/articles/electrolyte), which leads to the shuttle effect and results in capacity loss over time.\nThe operating temperature and cycling rate also play significant roles in determining the lifespan of Li-S batteries.\n\n# Research\n\n# Commercialization\nAs of 2021 few companies had been able to commercialize the technology on an industrial scale.\nCompanies such as Sion Power have partnered with [Airbus Defence and Space](https://bliptext.com/articles/airbus-defence-and-space) to test their lithium sulfur battery technology.\nAirbus Defense and Space successfully launched their prototype [High Altitude Pseudo-Satellite](https://bliptext.com/articles/high-altitude-pseudo-satellite) (HAPS) aircraft powered by solar energy during the day and by lithium sulfur batteries at night in real life conditions during an 11-day flight.\nThe batteries used in the test flight utilized Sion Power's Li–S cells that provide 350 W⋅h/kg.\nSion originally claimed to be in the process of volume manufacturing with availability by end of 2017; however more recently it can be seen that they have dropped work on their lithium sulfur battery in favor of a lithium-metal battery.\nBritish firm OXIS Energy developed prototype lithium sulfur batteries.\nTogether with [Imperial College London](https://bliptext.com/articles/imperial-college-london) and [Cranfield University](https://bliptext.com/articles/cranfield-university), they published [equivalent-circuit-network](https://bliptext.com/articles/equivalent-circuit-network) models for its cells.\nWith Lithium Balance of Denmark they built a prototype scooter battery system primarily for the Chinese market, which had a capacity of 1.2kWh using 10Ah Long Life cells, and weighed 60% less than lead acid batteries with a significant increase in range.\nThey also built a 3U, 3,000W⋅h Rack-Mounted Battery that weighed only 25kg and was said to be fully scalable.\nThey claimed their Lithium-Sulfur batteries would cost about $200/kWh in mass production.\nHowever, the firm entered bankruptcy (insolvency) status in May 2021.\n[Sony](https://bliptext.com/articles/sony), which also commercialized the first lithium-ion battery, planned to introduce lithium–sulfur batteries to the market in 2020, but has provided no updates since the initial announcement in 2015.\nMonash University's Department of Mechanical and Aerospace Engineering in Melbourne, Australia developed an ultra-high capacity Li–S battery that has been manufactured by partners at the Fraunhofer Institute for Material and Beam Technology in Germany.\nIt is claimed the battery can provide power to a smartphone for five days.\nIn 2022, the German company Theion claimed to introduce lithium–sulfur batteries for mobile devices in 2023 and for vehicles by 2024.\nIn January 2023, [Houston, Texas](https://bliptext.com/articles/houston-texas) company [Zeta Energy](https://bliptext.com/articles/zeta-energy) was awarded $4 million by the [United States Department of Energy](https://bliptext.com/articles/united-states-department-of-energy) [ARPA-E](https://bliptext.com/articles/arpa-e) program to advance its lithium-sulfur batteries based on a sulfurized-carbon cathode and a vertically-aligned carbon nanontube anode.\nIn June 2023, [San Jose, California](https://bliptext.com/articles/san-jose-california) company Lyten started up a pilot production line making about 100 batteries a day.\nIn 2024, Lyten announced plans a billion-dollar gigafactory in Reno, Nevada, to build up to 10 gigawatt-hours of lithium–sulfur batteries annually.","current_revision":null,"created_by":"kACnuQmH5k9Nr5VNVEpVeg7XpvUmMctD","created_at":"2025-01-26T11:06:50.133Z","updated_at":"2025-01-26T11:06:50.133Z","search_vector":"'batteri':3 'lithium':1 'sulfur':2","search_content":" \n \n**Etow:** 450 Wh/kg \n**Etos:** 550 Wh/L \n**Ctode:** C/5 nominal \n**Nomv:** Cell [voltage](https://bliptext.com/articles/volt) varies nonlinearly in the range 2.5–1.7V during discharge; batteries often packaged for 3V \n**Cd:** In question \n \n\n# \nThe **lithium–sulfur battery** (Li–S battery) is a type of [rechargeable battery](https://bliptext.com/articles/rechargeable-battery).\nIt is notable for its high [specific energy](https://bliptext.com/articles/specific-energy).\nThe low [atomic weight](https://bliptext.com/articles/atomic-weight) of [lithium](https://bliptext.com/articles/lithium) and moderate [atomic weight](https://bliptext.com/articles/atomic-weight) of [sulfur](https://bliptext.com/articles/sulfur) means that Li–S batteries are relatively light (about the density of water).\nThey were used on the longest and highest-altitude unmanned [solar-powered](https://bliptext.com/articles/solar-powered) aeroplane flight (at the time) by [Zephyr 6](https://bliptext.com/articles/airbus-zephyr) in August 2008.\nLithium–sulfur batteries may displace [lithium-ion](https://bliptext.com/articles/lithium-ion) cells because of their higher energy density and reduced cost.\nThis is due to two factors.\nFirst the use of [sulfur](https://bliptext.com/articles/sulfur) instead of a less energy dense and more expensive substances such as cobalt and/or iron compounds found in [lithium-ion batteries](https://bliptext.com/articles/lithium-ion-battery).\nSecondly, the use of metallic lithium instead of intercalating lithium ions allows for much higher energy density, as less substances are needed to hold \"lithium\" and lithium is directly oxidized.\nLi–S batteries offer specific energies on the order of 550[Wh](https://bliptext.com/articles/watt-hour)/[kg](https://bliptext.com/articles/kilogram), while lithium-ion batteries are in the range of 150–260[Wh](https://bliptext.com/articles/watt-hour)/[kg](https://bliptext.com/articles/kilogram).\nLi–S batteries with up to 1,500 charge and discharge cycles were demonstrated in 2017, but cycle life tests at commercial scale and with lean electrolyte have not been completed.\nAs of early 2021, none were commercially available.\nIssues that have slowed acceptance include the polysulfide \"shuttle\" effect that is responsible for the progressive leakage of active material from the cathode, resulting in too few recharge cycles.\nAlso, sulfur cathodes have low conductivity, requiring extra mass for a conducting agent in order to exploit the contribution of active mass to the capacity.\nVolume expansion of the sulfur cathode during S to Li2S conversion and the large amount of electrolyte needed are also issues.\nIn the early 2000s, however, scientists began to make progress creating high-stability sulfurized-carbon cathodes and by 2020, scientists at Rice University had demonstrated batteries based on sulfurized carbon cathodes that retained >70% of their capacity after 1000 cycles.\nBy 2023, [Zeta Energy](https://bliptext.com/articles/zeta-energy) a Texas-based startup announced that multiple national laboratories had independently verified that its lithium-sulfur batteries based on sulfurized-carbon cathodes were polysulfide shuttle free.\nThe competitive advantages of sulfurized-carbon cathodes (e.g., sulfurized polyacrylonitrile, also known as SPAN) were highlighted by a quantitative analysis performed by researchers at [University of Maryland, College Park](https://bliptext.com/articles/university-of-maryland-college-park) and [Pacific Northwest National Laboratory](https://bliptext.com/articles/pacific-northwest-national-laboratory) in 2024.\nTheir polysulfide shuttle free feature facilitates proper operation under lean electrolyte conditions ( 5 mg·cm−2, a carbon content of \nHistorically, the \"shuttle\" effect is the main cause of degradation in a Li–S battery.\nThe lithium polysulfide Li2Sx (6≤x≤8) is highly soluble in the common electrolytes used for Li–S batteries.\nThey are formed and leaked from the cathode and they diffuse to the anode, where they are reduced to short-chain polysulfides and diffuse back to the cathode where long-chain polysulfides are formed again.\nThis process results in the continuous leakage of active material from the cathode, lithium corrosion, low coulombic efficiency and low battery life.\nMoreover, the \"shuttle\" effect is responsible for the characteristic self-discharge of Li–S batteries, because of slow dissolution of polysulfide, which occurs also in rest state.\nThe \"shuttle\" effect in a Li–S battery can be quantified by a factor fc (0 < fc < 1), evaluated by the extension of the charge voltage plateau.\nThe factor fc is given by the expression:\nwhere ks, qup, [Stot] and Ic are respectively the kinetic constant, specific capacity contributing to the anodic plateau, the total sulfur concentration and charge current.\nIn 2022, researchers reported the use of a cathode made from [carbon nanofibers](https://bliptext.com/articles/carbon-nanofibers).\nElemental sulfur was deposited onto the carbon substrate (cf. [physical vapor deposition](https://bliptext.com/articles/physical-vapor-deposition)), which formed the rare and usually metastable monoclinic [γ-Sulfur](https://bliptext.com/articles/allotropes-of-sulfur) allotrope.\nThis allotrope reversibly reacts to without the formation of intermediate polysulfides.\nTherefore, carbonate electrolytes, which commonly react with those polysulfides, can be used instead of the rather dangerous ether based electrolytes (low flash and boiling points).\nIts initial capacity was 800 Ah/kg (classical LiCoO2/graphite batteries have a cell capacity of 100 Ah/kg).\nIt decayed only very slowly, on average 0.04% each cycle, and retained 658 Ah/kg after 4000 cycles (82%).\n\n# Electrolyte\nConventionally, Li–S batteries employ a liquid organic electrolyte, contained in the pores of PP separator.\nThe electrolyte plays a key role in Li–S batteries, acting both on \"shuttle\" effect by the polysulfide dissolution and the SEI stabilization at anode surface.\nIt has been demonstrated that the electrolytes based on organic carbonates commonly employed in Li-ion batteries (i.e. PC, [EC](https://bliptext.com/articles/ethylene-carbonate), D[EC](https://bliptext.com/articles/ethylene-carbonate) and mixtures of them) are not compatible with the chemistry of Li–S batteries.\nLong-chain polysulfides undergo nucleophilic attack on electrophilic sites of carbonates, resulting in the irreversible formation of by-products as [ethanol](https://bliptext.com/articles/ethanol), m[ethanol](https://bliptext.com/articles/ethanol), [ethylene glycol](https://bliptext.com/articles/ethylene-glycol) and [thiocarbonates](https://bliptext.com/articles/thiocarbonate).\nIn Li–S batteries are conventionally employed cyclic ethers (as [DOL](https://bliptext.com/articles/dioxolane)) or short-chain ethers (as [DME](https://bliptext.com/articles/dimethyl-ether)) as well as the family of glycol ethers, including DEG[DME](https://bliptext.com/articles/dimethyl-ether) and TEG[DME](https://bliptext.com/articles/dimethyl-ether).\nOne common electrolyte is 1M [LiTFSI](https://bliptext.com/articles/lithium-bis-trifluoromethanesulfonyl-imide) in DOL:DME 1:1 vol. with 1%w/w di LiNO3 as additive for lithium surface passivation.\n\n# Safety\nBecause of the high potential energy density and the nonlinear discharge and charging response of the cell, a [microcontroller](https://bliptext.com/articles/microcontroller) and other safety circuitry is sometimes used along with [voltage regulators](https://bliptext.com/articles/voltage-regulator) to manage cell operation and [prevent rapid discharge](https://bliptext.com/articles/thermal-runaway).\n\n# Lifespan\nLithium-sulfur (Li-S) batteries have a shorter lifespan compared to traditional [Li-ion batteries](https://bliptext.com/articles/li-ion-batteries).\nRecent advancements in materials and [electrolyte](https://bliptext.com/articles/electrolyte) formulations have shown potential to extend its [cycle life](https://bliptext.com/articles/cycle-life) to over 1,000 cycles.\nOne of the primary factors limiting the lifespan of Li-S batteries is the dissolution of [polysulfides](https://bliptext.com/articles/polysulfides) in the [electrolyte](https://bliptext.com/articles/electrolyte), which leads to the shuttle effect and results in capacity loss over time.\nThe operating temperature and cycling rate also play significant roles in determining the lifespan of Li-S batteries.\n\n# Research\n\n# Commercialization\nAs of 2021 few companies had been able to commercialize the technology on an industrial scale.\nCompanies such as Sion Power have partnered with [Airbus Defence and Space](https://bliptext.com/articles/airbus-defence-and-space) to test their lithium sulfur battery technology.\nAirbus Defense and Space successfully launched their prototype [High Altitude Pseudo-Satellite](https://bliptext.com/articles/high-altitude-pseudo-satellite) (HAPS) aircraft powered by solar energy during the day and by lithium sulfur batteries at night in real life conditions during an 11-day flight.\nThe batteries used in the test flight utilized Sion Power's Li–S cells that provide 350 W⋅h/kg.\nSion originally claimed to be in the process of volume manufacturing with availability by end of 2017; however more recently it can be seen that they have dropped work on their lithium sulfur battery in favor of a lithium-metal battery.\nBritish firm OXIS Energy developed prototype lithium sulfur batteries.\nTogether with [Imperial College London](https://bliptext.com/articles/imperial-college-london) and [Cranfield University](https://bliptext.com/articles/cranfield-university), they published [equivalent-circuit-network](https://bliptext.com/articles/equivalent-circuit-network) models for its cells.\nWith Lithium Balance of Denmark they built a prototype scooter battery system primarily for the Chinese market, which had a capacity of 1.2kWh using 10Ah Long Life cells, and weighed 60% less than lead acid batteries with a significant increase in range.\nThey also built a 3U, 3,000W⋅h Rack-Mounted Battery that weighed only 25kg and was said to be fully scalable.\nThey claimed their Lithium-Sulfur batteries would cost about $200/kWh in mass production.\nHowever, the firm entered bankruptcy (insolvency) status in May 2021.\n[Sony](https://bliptext.com/articles/sony), which also commercialized the first lithium-ion battery, planned to introduce lithium–sulfur batteries to the market in 2020, but has provided no updates since the initial announcement in 2015.\nMonash University's Department of Mechanical and Aerospace Engineering in Melbourne, Australia developed an ultra-high capacity Li–S battery that has been manufactured by partners at the Fraunhofer Institute for Material and Beam Technology in Germany.\nIt is claimed the battery can provide power to a smartphone for five days.\nIn 2022, the German company Theion claimed to introduce lithium–sulfur batteries for mobile devices in 2023 and for vehicles by 2024.\nIn January 2023, [Houston, Texas](https://bliptext.com/articles/houston-texas) company [Zeta Energy](https://bliptext.com/articles/zeta-energy) was awarded $4 million by the [United States Department of Energy](https://bliptext.com/articles/united-states-department-of-energy) [ARPA-E](https://bliptext.com/articles/arpa-e) program to advance its lithium-sulfur batteries based on a sulfurized-carbon cathode and a vertically-aligned carbon nanontube anode.\nIn June 2023, [San Jose, California](https://bliptext.com/articles/san-jose-california) company Lyten started up a pilot production line making about 100 batteries a day.\nIn 2024, Lyten announced plans a billion-dollar gigafactory in Reno, Nevada, to build up to 10 gigawatt-hours of lithium–sulfur batteries annually.","revisionCount":0},"hasMore":false,"nextCursor":null}