Lithium Iodine Research Articles

Separation Effect of Graphene Sheets with N, O Codoping and Molybdenum Clusters for Reversible Lithium–Iodine Batteries

AbstractLithium–iodine (Li–I2) batteries with ideal discharge potential plateau and abundant iodine resources have attracted considerable attention. However, the poor electrical conductivity of iodine with high solubility in organic electrolytes, and the Li dendrite issue have severely limited the practical application of Li–I2 batteries. Herein, this work demonstrates that the bifunctionalization of polypropylene (PP) separator with molybdenum clusters on N, O codoped graphene nanosheets (Mo‐rGO@PP) is efficient to promote the reversible redox reactions of polyiodides to suppress the shuttle effect, and enhance the Li affinity for the uniform Li plating/stripping. Typically, the Li symmetric battery assembled with Mo‐rGO@PP separator exhibits an ultralong lifespan of >2000 h with a low overpotential of <25 mV at 10 mA cm−2. With such a separation effect to effectively suppress the polyiodide shuttle and dendrite growth, the Li–I2 battery delivers a long cycle life of over 6000 cycles with a reversible capacity of 170 mAh g−1 at 10 C. With deep insights into the ion flux and redox regulation, this work demonstrates the promising advances via the separation effect for developing high‐performance redox batteries.

Understanding the Structural Properties and the Stability of the Solid Electrolyte Material Li4PS4I with First-Principles Simulations

In this study, First-Principles simulations were utilized to investigate the structural characteristics and address some of the stability issues of the solid electrolyte material Li4PS4I. The computational results indicate that unlike most ion-conducting systems, Li4PS4I does not exhibit a fully ordered phase that is stable at ambient conditions. Instead, the material prefers a disordered configuration at room temperature, and the configurational entropy arising from the disordered nature of the material plays a critical role in stabilizing the material. Additionally, a plausible metastable fully ordered phase of the material was identified, which was used to examine the structural properties and interface stability with Li anode of the material. Our analysis of the interface stability revealed that Li4PS4I is likely to react with Li anode, but the reaction is limited to the surface layers of the material. Furthermore, the comparison of the idealized interfaces with Li anode of Li4PS4I with the analogue γ − Li3PS4 suggests that less P-S bonds are broken for Li4PS4I, which is attributed to the presence of Iodine on the surface. This finding supports the argument that the incorporation of Lithium iodine into sulfide-based electrolytes enhances their stability when in contact with a Li anode.

50 Years with Lithium Batteries

The discovery of 7 still available primary battery systems involving the lithium anode occurred some 50 years ago in the period of 1970 to 1973. The discoveries (and many others which did not survive competition) were made in a number of industrial and academic laboratories, including Union Carbide’s Parma Technical Center, where I led the lithium research group. These studies were part of a world-wide search to find satisfactory cathodes and electrolytes to take advantage of the remarkable properties of lithium as an anode. The well-known advantages of lithium give it almost ideal properties as a battery anode except that it is very difficult to handle in air due to reaction with both oxygen and nitrogen and reacts with any solvent containing dissociable protons to form hydrogen gas. The work by W.S. Harris in 19581 established that solvents such as propylene carbonate, ethylene carbonate and butyrolactone were stable in the presence of lithium metal giving impetus to the search for appropriate lithium battery cathodes.The anodes all utilized thin lithium foil (usually in the range of 100 to 200 μm) contacted by a nickel, copper or stainless steel tab, or container body, while the cathodes and electrolytes were of three types: 1.) solid cathode with liquid electrolytes, 2.) solid cathode with solid electrolyte and 3.) liquid cathode with liquid electrolyte. Two solid cathodes with liquid electrolyte were carbon monofluoride and manganese dioxide in the 3V class came from laboratories in Japan. A third solid cathode in the 1.5V class was iron disulfide (the mineral pyrites) came from our laboratory in the U.S. in this period, but was not disclosed until 1978. This cathode was first discussed in a high temperature cell with lithium alloy anodes by Argonne National Laboratory in the U.S.The lithium iodine cell with an in-situ formed LiI solid electrolyte was discovered in the laboratories of the Jet Propulsion Laboratory of NASA and developed independently by several U.S. companies, mainly Catalyst Research Corp. and Wilson Greatbatch Ltd. A key component of the cell is polyvinylpyridine which is mixed with iodine under heat to form a liquid slurry, which is poured into the cathode compartment of the cellLithium/sulfur dioxide was the first liquid cathode-liquid electrolyte cell and was patented by American Cyanimid Co.in the U.S. in 19712. An example in the patent corresponds closely to the present contents involving a lithium sheet anode with a carbon collector for the cathode and an electrolyte containing LiBr salt with sulfur dioxide and acetonitrile solvents. Work at our laboratory discovered the lithium/thionyl chloride and lithium/sulfuryl chloride systems. The patent was filed in 1971, but patent acceptance was delayed by an interference proceeding until 19833. The feature of these systems was the absence of any co-solvent such as acetonitrile which allowed higher energy density. The properties of these batteries as available will be discussed and the systems compared for advantages and disadvantages

Highly Thermally/Electrochemically Stable I−/I3−Bonded Organic Salts with High I Content for Long‐Life Li–I2Batteries

AbstractRechargeable lithium–iodine batteries are highly attractive energy storage systems featuring high energy density, superior power density, sustainability, and affordability owing to the promising redox chemistries of iodine. However, severe thermodynamic instability and shuttling issues of the cathode have plagued the active iodine loading, capacity retention and cyclability. Here the development of highly thermally and electrochemically stable I−/I3−‐bonded organic salts as cathode materials for Li–I2batteries is reported. The chemical bonding of iodine/polyiodide ions with organic groups allows up to 80 wt% iodine to be effectively stabilized without sacrificing fast and reversible redox reaction activity. Thus, the shuttle effect is significantly inhibited, which improves cathode capacity and restrains side‐reactions on the Li anode. As a result, such cathodes afford Li–I2batteries a specific capacity of 173.6 mAh g−1methylamine hydroiodide (MAI)(217 mAh g−1I) at 0.5 C, superior rate capability of 133.1 mAh g−1MAIat 50 C, and ultrahigh capacity retention rate of 98.3% over 10000 cycles (5 months). In‐situ, ex‐situ spectral characterizations and density functional theory calculations clarify the robust chemical interaction between iodides and organic groups. The cathode chemistries elucidated here propel the development of Li–I2batteries and are expected to be extended to other metal‐iodine battery technology.

Two-Electron Redox Chemistry Enabled High-Performance Iodide-Ion Conversion Battery.

A single-electron transfer mode coupled with the shuttle behavior of organic iodine batteries results in insufficient capacity, a low redox potential, and poor cycle durability. Sluggish kinetics are well known in conventional lithium-iodine (Li-I) batteries, inferior to other conversion congeners. Herein, we demonstrate new two-electron redox chemistry of I- /I+ with inter-halogen cooperation based on a developed haloid cathode. The new iodide-ion conversion battery exhibits a state-of-art capacity of 408 mAh gI-1 with fast redox kinetics and superior cycle stability. Equipped with a newly emerged 3.42 V discharge voltage plateau, a recorded high energy density of 1324 Wh kgI-1 is achieved. Such robust redox chemistry is temperature-insensitive and operates efficiently at -30 °C. With systematic theoretical calculations and experimental characterizations, the formation of Cl-I+ species and their functions are clarified.

Two‐Electron Redox Chemistry Enabled High‐Performance Iodide‐Ion Conversion Battery

AbstractA single‐electron transfer mode coupled with the shuttle behavior of organic iodine batteries results in insufficient capacity, a low redox potential, and poor cycle durability. Sluggish kinetics are well known in conventional lithium–iodine (Li−I) batteries, inferior to other conversion congeners. Herein, we demonstrate new two‐electron redox chemistry of I−/I+ with inter‐halogen cooperation based on a developed haloid cathode. The new iodide‐ion conversion battery exhibits a state‐of‐art capacity of 408 mAh gI−1 with fast redox kinetics and superior cycle stability. Equipped with a newly emerged 3.42 V discharge voltage plateau, a recorded high energy density of 1324 Wh kgI−1 is achieved. Such robust redox chemistry is temperature‐insensitive and operates efficiently at −30 °C. With systematic theoretical calculations and experimental characterizations, the formation of Cl−I+ species and their functions are clarified.

Dual-functional iodine photoelectrode enabling high performance photo-assisted rechargeable lithium iodine batteries

We demonstrate an integrated photo-assisted rechargeable lithium-iodine battery by using a hybrid I2/N719-dye/TiO2 composite as a dual-functional photoelectrode, which could convert solar energy into electrical power and store it simultaneously.

Studies on the characteristics of $$\hbox {TiO}_2$$ photoanode and flavanol pigment as a sensitiser for DSSC applications

In the present work, dye-sensitised solar cell (DSSC) is fabricated using natural dye (Tecoma Stans)-sensitised $$\hbox {TiO}_{\mathrm {2\, }}$$ as the photoanode, platinum as the counter electrode and lithium iodide and iodine as the electrolyte. Initially, $$\hbox {TiO}_{\mathrm {2\, }}$$ nanoparticles are synthesised by the sol–gel technique using glacial acetic acid as the hydrolysing agent. The photoanodes are prepared by the Doctor Blade technique using the synthesised nanoparticles coated onto the fluorine-doped tin oxide (FTO) substrate and annealed at 400, 500 and $$600^{\circ }\hbox {C}$$ for 30 min. Structural analysis shows the anatase phase of the $$\hbox {TiO}_{\mathrm {2}}$$ thin film with a tetragonal crystal structure. The optical transmittance is found to be around 95% with an optical band gap close to 3.1 eV and increases with an increase in annealing temperature. From the PL emission spectra, the excitation of the titania band is observed. The pigment flavan-4-ol which acts as a sensitiser is extracted from Tecoma Stans flower. From the absorption study of the pigment, the active region of radiation and the band gap are found to be around 550 nm and 2 eV respectively. FTIR analysis of the pigment shows a stable structure similar to that of the prepared photoanodes. CV analysis of the sensitiser shows maximum oxidation within the active region. Field emission scanning electron microscope (FE-SEM) analysis shows that the prepared photoanode ( $$600^{\circ }\hbox {C}$$ ) has spherical shape. The overall photoconversion efficiency of Tecoma Stans-sensitised $$\hbox {TiO}_{\mathrm {2}}$$ photoanode is 0.4491%.

Inclusion complexation enhanced cycling performance of iodine/carbon composites for lithium–iodine battery

High-performance lithium–iodine (Li–I2) battery has gained increasing attention because of its high energy density, high power density, and low cost. However, the high solubility of iodine species in electrolyte severely deteriorates the electrochemical performance of a Li–I2 cell. Realizing stable cycling performance of iodine cathode while retaining its high specific capacity and high Coulombic efficiency remains a huge challenge. In this work, three water-soluble nonionic polymers, including methyl-beta-cyclodextrin (MβCD), polyvinylpyrrolidone (PVP) and amylose corn starch (ACS), are employed for coating iodine/carbon composites with a high content of iodine. The results reveal that inclusion complexes with linear iodine crystal can be formed on the surface of composites. Li–I2 batteries using these polymer-modified iodine/carbon composites as cathode materials show enhanced electrochemical performance in terms of cycling stability and Coulombic efficiency. This study sheds light on the importance of inclusion compounds of iodine and therefore sets a pathway to fabricate high-performance Li–I2 battery.

Preparation of a Z-Iodoalkene through Stork-Zhao-Wittig Olefination, Stereo-retentive Lithium–iodine Exchange and Z-Boronic acid Pinacol Ester Synthesis

Preparation of a Z-Iodoalkene through Stork-Zhao-Wittig Olefination, Stereo-retentive Lithium–iodine Exchange and Z-Boronic acid Pinacol Ester Synthesis

High-Performance Quasi-Solid-State MXene-Based Li-I Batteries.

Lithium–iodine (Li–I) batteries have attracted tremendous attention due to their high energy and power densities as well as the low cost of iodine. However, the severe shuttle effect of iodine species and the uncontrollable lithium dendrite growth have strongly hindered their practical applications. Here we successfully develop a quasi-solid-state Li–I battery enabled by a MXene-based iodine cathode and a composite polymer electrolyte (CPE) containing NaNO3 particles dispersing in a pentaerythritol-tetraacrylate-based (PETEA-based) gel polymer electrolyte. As verified by experimental characterizations and first-principle calculations, the abundant functional groups on the surface of MXene sheets provide strong chemical binding to iodine species, and therefore immobilize their shuttling. The PETEA-based polymer matrix simultaneously suppresses the diffusion of iodine species and stabilizes the Li anode/CPE interface against dendrite growth. The NaNO3 particles act as an effective catalyst to facilitate the transformation kinetics of LiI3 on the cathode. Owing to such synergistic optimization, the as-developed Li–I batteries deliver high energy/power density with long cycling stability and good flexibility. This work opens up a new avenue to improve the performance of Li–I batteries.

A Sensitive LC-MS/MS Method for Palytoxin Using Lithium Cationization.

Palytoxin (PlTX) and analogues are produced by certain dinoflagellates, sea anemones, corals and cyanobacteria. PlTX can accumulate in the food chain and when consumed it may cause intoxication with symptoms like myalgia, weakness, fever, nausea, and vomiting. The analysis of PlTXs is challenging, and because of the large molecular structure, it is difficult to develop a sensitive and selective liquid chromatography-mass spectrometry (LC-MS/MS) method. In this work, an LC-MS/MS method was developed to analyse PlTXs with use of lithium iodine and formic acid as additives in the mobile phase. For method development, initially, LC-hrMS was used to accurately determine the elemental composition of the precursor and product ions. The main adduct formed was [M + H + 2Li]3+. Fragments were identified with LC-hrMS and these were incorporated in the LC-MS/MS method. A method of 10 min was developed and a solid phase extraction clean-up procedure was optimised for shellfish matrix. The determined limits of detection were respectively 8 and 22 µg PlTX kg−1 for mussel and oyster matrix. Oysters gave a low recovery of approximately 50% for PlTX during extraction. The method was successfully in-house validated, repeatability had a relative standard deviation less than 20% (n = 5) at 30 µg PlTX kg−1 in mussel, cockle, and ensis, and at 60 µg PlTX kg−1 in oyster.

Anchoring Iodine to N-Doped Hollow Carbon Fold-Hemisphere: Toward a Fast and Stable Cathode for Rechargeable Lithium-Iodine Batteries.

Rechargeable lithium-iodine batteries with abundant raw materials and low cost are promising electrochemical energy storage systems. Herein, we demonstrate that anchoring iodine to N-doped hollow carbon fold-hemisphere (N-FHS) is highly efficient to overcome slow kinetics and low stability of iodine cathode in lithium-iodine batteries. For the first time, significant effects of carbon framework architecture on the lithium storage performance of iodine cathode are studied in detail. Notably, the fold-hemisphere (N-FHS) is more effective than the similar architectures, such as hollow sphere (N-S) or hemisphere (N-HS), in modifying slow ion transport capability and fast structure deterioration. The superior property of iodine@N-FHS is associated with its highly porous structure and strong interconnection to iodine. The iodine deterioration mechanism in lithium-iodine battery is analyzed, and the deterioration processes of iodine in different carbon frameworks during cycling are investigated. This work opens a new avenue to solve the key problems in lithium-iodine batteries, allowing it an important candidate for energy storage.

Healing High-Loading Sulfur Electrodes with Unprecedented Long Cycling Life: Spatial Heterogeneity Control.

Self-healing capability helps biological systems to maintain their survivability and extend their lifespan. Similarly, self-healing is also beneficial to next-generation secondary batteries because high-capacity electrode materials, especially the cathodes such as oxygen or sulfur, suffer from shortened cycle lives resulting from irreversible and unstable phase transfer. Herein, by mimicking a biological self-healing process, fibrinolysis, we introduced an extrinsic healing agent, polysulfide, to enable the stable operation of sulfur microparticle (SMiP) cathodes. An optimized capacity (∼3.7 mAh cm-2) with almost no decay after 2000 cycles at a high sulfur loading of 5.6 mg(S) cm-2 was attained. The inert SMiP is activated by the solubilization effect of polysulfides whereas the unstable phase transfer is mediated by mitigated spatial heterogeneity of polysulfides, which induces uniform nucleation and growth of solid compounds. The comprehensive understanding of the healing process, as well as of the spatial heterogeneity, could further guide the design of novel healing agents (e.g., lithium iodine) toward high-performance rechargeable batteries.

Understanding the effects of 3D porous architectures on promoting lithium or sodium intercalation in iodine/C cathodes synthesized via a biochemistry-enabled strategy.

Rechargeable sodium-iodine and lithium-iodine batteries have been demonstrated to be promising and scalable energy-storage devices, but their development has been seriously limited by challenges such as their inferior stability and the poor kinetics of iodine. Anchoring iodine to 3D porous carbon is an effective strategy to overcome these defects; however, both the external architecture and internal microstructure of the 3D porous carbon host can greatly affect the ion intercalation of iodine/C electrodes. To realize the full potential of iodine electrodes, a biochemistry-enabled route was developed to enable the controllable design of different 3D porous architectures, from hollow microspheres to 3D foam, for use in iodine/C cathodes. Two types of spores with spherical cells, i.e. Cibotium Barometz (C. Barometz) and Oetes Sinesis (O. Sinesis), are employed as bio-precursors. By carefully controlling the degree of damage on the bio-precursors, different targeted carbon hosts were fabricated. Systematic studies were carried out to clarify the structural effects on modifying the ion-intercalation capabilities of the iodine/C cathodes in lithium-iodine and sodium-iodine batteries. Our results demonstrate the profound performance improvements of both 3D bio-foam and hollow sphere because their hierarchically porous structures can strongly immobilize iodine. Notably, the 3D bio-foam based iodine composites achieve faster ion kinetics and enhanced rate capability than their hollow sphere based counterparts. This was attributed to their higher micro/mesopore volume, larger surface area and improved packing density, which result in the highly efficient adsorption of iodine species. By virtue of the thinnest slices, the iodine/bio-foam derived from C. Barometz spores achieves the best high-rate long-term cycling capability, which retains 94% and 91% of their capacities in lithium-iodine and sodium-iodine batteries after 500 cycles, respectively. With the help of the biochemistry-assisted technique, our study provides a much-needed fundamental insight for the rational design of 3D porous iodine/C composites, which will promote a significant research direction for the practical application of lithium/sodium-iodine batteries.

Encapsulating a high content of iodine into an active graphene substrate as a cathode material for high-rate lithium–iodine batteries

Iodine-active graphene composites as cathode materials for rechargeable Li–I2 batteries are fabricated. Soluble iodine redox species can be confined in the porous active graphene substrate, making the composites promising materials for high-rate energy storage devices.

High Energy Efficiency and Stability for Photoassisted Aqueous Lithium–Iodine Redox Batteries

We demonstrated photoassisted lithium–iodine (Li–I2) redox cells integrated with a hematite photoelectrode that are applicable to energy storage systems (ESSs). The hematite photoelectrode presents low cost, light absorption in the visible light region, and inertness to aqueous electrolytes, which allow for stable production of photocurrent under illumination. In the aqueous Li–I2 redox cells, the harnessing of photoenergy generates photocarriers that promote the I– oxidation process without electrolysis of the aqueous solution. The energy efficiency for the photoassisted charge process is ∼95.4%, which is ∼20% higher than that in the absence of illumination at a current rate of 0.075 mA cm–2. The hematite is profoundly stable in aqueous I–/I3– catholyte and exhibits over 600 h of cycling without noticeable performance decay and photocorrosion. This achievement highlights photoinduced ESSs with improved energy efficiency.

A Novel Small-Molecule Compound of Lithium Iodine and 3-Hydroxypropionitride as a Solid-State Electrolyte for Lithium–Air Batteries

A novel small-molecule compound of lithium iodine and 3-hydroxypropionitrile (HPN) has been successfully synthesized. Our combined experimental and theoretical studies indicated that LiIHPN is a Li-ion conductor, which is utterly different from the I(-)-anion conductor of LiI(HPN)2 reported previously. Solid-state lithium-air batteries based on LiIHPN as the electrolyte exhibit a reversible discharge capacity of more than 2100 mAh g(-1) with a cyclic performance over 10 cycles. Our findings provide a new way to design solid-state electrolytes toward high-performance lithium-air batteries.

Regioselective Lithium-Iodine Exchange-Initiated Cleavage of 2-Iodomethyl-1,3-dioxanes: A Complex-Induced Proximity Effect.

Lithium-iodine exchange-initiated fragmentation of a series of 4-substituted 2-iodomethyl-1,3-dioxanes proceeds rapidly and regioselectively to afford enol ether alcohols by preferential cleavage of the less congested C(2)-O(1) bond. The results demonstrate that a complex-induced proximity effect (CIPE) is likely responsible for the selectivity of the cleavage.

Ultra-small B2O3 nanocrystals grown in situ on highly porous carbon microtubes for lithium–iodine and lithium–sulfur batteries

B2O3-modified carbon microtubes, which possess a highly porous structure and well-dispersed ultra-small B2O3 nanocrystals (ca. <5 nm) in the tube wall, are successfully fabricated for lithium–iodine and lithium–sulfur batteries.