Lithium seawater

Lithium-Metal Salt secondary batteries are analogous to the Lithium-seawater primary battery [3]. A Li -ion solid electrolyte separates a nonaqueous anolyte and an aqueous cathode. For example, a Lithium anode with a carbonate anolyte and an aqueousFe(CN)g /Fe(CN)g cathode has been shown to give aflat voltage F 3.4 V with an efficiency that increases with the molar ratio of iron cyanide in the cathode solution [27]. This promising approach requires development of a Li-ion solid electrolyte having a (Tli > 10 8/cm at room temperature that is stable to an acidic cathode solution and is not reduced by contact with a Li° dendrite on the anode side. 

In fact, the copolymers (143), from the ROM co-polymerization of mixtures of the endo-exo norbornenemethoxy-cyclotriphosphazenes (142a) and (142b) (both prepared from 139), were successively reacted with KOBu, aqueous HCl, and LiOH to transform the 4-(propylcarboxalato)phenoxy side groups (R ) first into the -COOH and finally into the COO Li to synthesize novel lithium-ion conductive polymers as prospective membranes for Lithium-Seawater Batteries. The dependence of ion transport and hydrophobic properties on the polymer composition were discussed. ... 

Welna, D. T., Stone, D. A., Allcock, H. R., Lithium-ion conductive polymers as prospective membranes for lithium-seawater batteries, Chemistry of Materials, 2006, 18, 4486-4492. 

Brine Sources. Lithium occurs naturally in brines from salars, saline lakes and seawater, od-fteld waters, and geothermal brines. Of these sources, lithium is produced only from brines of two salars. 

Occurrence. Numerous brines contain lithium in minor concentrations. Commercially valuable natural brines are located at Silver Peak, Nevada (400 ppm) (40,41), and at Seades Lake, California (50 ppm) (42,43). Great Salt Lake brine contains 40 ppm and is a source not yet exploited. Seawater contains less than 0.2 ppm. Lithium production started at Silver Peak in the 1970s. The concentration of lithium in the brine is diminishing, and now the principal production occurs from brine in the Salar de Atacama, Chile. 

Good results are obtained with oxide-coated valve metals as anode materials. These electrically conducting ceramic coatings of p-conducting spinel-ferrite (e.g., cobalt, nickel and lithium ferrites) have very low consumption rates. Lithium ferrite has proved particularly effective because it possesses excellent adhesion on titanium and niobium [26]. In addition, doping the perovskite structure with monovalent lithium ions provides good electrical conductivity for anodic reactions. Anodes produced in this way are distributed under the trade name Lida [27]. The consumption rate in seawater is given as 10 g A ar and in fresh water is... 

This technique has been used to determine a number of elements in seawater, including lithium [826], barium [74], lead [827], rubidium [840], uranium [828], and copper [298,299]. It has not been extensively applied. 

Tseng et al. [69] determined 60cobalt in seawater by successive extractions with tris(pyrrolidine dithiocarbamate) bismuth (III) and ammonium pyrrolidine dithiocarbamate and back-extraction with bismuth (III). Filtered seawater adjusted to pH 1.0-1.5 was extracted with chloroform and 0.01 M tris(pyrrolidine dithiocarbamate) bismuth (III) to remove certain metallic contaminants. The aqueous residue was adjusted to pH 4.5 and re-extracted with chloroform and 2% ammonium pyrrolidine thiocarbamate, to remove cobalt. Back-extraction with bismuth (III) solution removed further trace elements. The organic phase was dried under infrared and counted in a ger-manium/lithium detector coupled to a 4096 channel pulse height analyser. Indicated recovery was 96%, and the analysis time excluding counting was 50-min per sample. 

Chassery et al. [97] studied the 87Sr/86Br composition in marine sediments, observing excellent agreement between results obtained by ICP-MS and thermal ionisation mass spectrometry. Low level a-spectrometry with lithium drifted germanium detectors has been used to determine 90strontium in seawater [59]. 

Taylor and Zeitlin [43] described an X-ray fluorescence procedure for the determination of total sulfur in seawater. They studied the matrix effects of sodium chloride, sodium tetraborate, and lithium chloride and show that the X-ray fluorescence of sulfur in seawater experiences an enhancement by chloride and a suppression by sodium that fortuitously almost cancel out. The use of soft scattered radiation as an internal standard is ineffective in compensating for matrix effects but does diminish the effects of instrument variations and sample inhomogeneity. 

Lithium is enriched in high temperature (c. 350°C) vent fluids by a factor of 20-50 relative to seawater (Edmond et al. 1979 Von Damm 1995). The Li isotopic compositions of marine hydrothermal vent fluids ranged from MORB-like to heavier compositions (see... 

Lithium isotope data from carbonate shells of other marine invertebrates have been reported. Hoefs and Sywall (1997) determined isotopic compositions of seven different species of modem bivalves from the North Sea coast. These samples had a relatively small range in 5 Li (+15 to +21), which corresponds well to the seawater-carbonate offset from inorganic calcite and modem corals (Marriott et al. 2004). 

You CF, Chan LH, Gieskes JM, Klinkhammer GP (2004) Seawater intrusion through the oceanic crust and carbonate sediment in the Equatorial Pacific Lithium abundance and isotopic evidence. Geophys Res Lett 30 (in press)... 

Rubidium does not exist in its elemental metallic form in nature. However, in compound forms it is the 22nd most abundant element on Earth and, widespread over most land areas in mineral forms, is found in 310 ppm. Seawater contains only about 0.2 ppm of rubidium, which is a similar concentration to lithium. Rubidium is found in complex minerals and until recently was thought to be a rare metal. Rubidium is usually found combined with other Earth metals in several ores. The lepidolite (an ore of potassium-lithium-aluminum, with traces of rubidium) is treated with hydrochloric acid (HCl) at a high temperature, resulting in lithium chloride that is removed, leaving a residue containing about 25% rubidium. Another process uses thermochemical reductions of lithium and cesium ores that contain small amounts of rubidium chloride and then separate the metals by fractional distillation. 

Lithium was first discovered in 1817 by Arfvedsen in its sdicoaluminate mineral, petahte. However, the metal first was isolated from its mineral by Bunsen and Matthiesen in 1855. Lithium is distributed widely in nature. Its concentration in the earth s crust is 20 mg/kg, and in seawater is 0.18mg/L. It is found in many chloride brines at varying but significant amounts. The principal minerals are ... 

Lithium Ion Lithium Polymer Batteries Rechargers Accessories Seawater-Activated Batteries Integrated Communications Systems... 

According to the latest estimates of Skinner [18], elements potentially recoverable from seawater are sodium, potassium, magnesium, calcium, strontium, chlorine, bromine, boron, and phosphorus because of their practically unlimited presence in the ocean. After improving respective technologies, recovery of the following elements is expected to become profitable as well lithium, rubidium, uranium, vanadium, and molybdenum. Additional profit can be gained since desalinated water will probably be obtained as a by-product. This could be important for countries with a very limited number of freshwater sources (e.g., Israel, Saudi Arabia). 

Lithium concentration in seawater does not exceed 0.17 mg/L. Nevertheless, the ocean is considered to be the most promising source of this element in the near future [107]. The overall inventory of lithium in the world s oceans is approximately 2.6x 10 tons [2]. With lithium so accessible, continual growth of lithium demand depends solely on new developments and expansion of its recovery from sea. 

The problem of lithium recovery from land-based hydromineral sources is very similar to the problem encountered in its recovery from seawater. Coprecipitation, extraction, and ion exchange, the methods used in both instances are practically the same. 

Investigation of the performance of ISMA-1 sorbents, when used to recover lithium from seawater, has yielded the following information (1) Li ion distribution coefficients of 4x lO" cm g prevail (Eq. (4) (2) the sorbents are easily regenerated with nitric acid (3) they exhibit a high capacity for Li ions of about 20 mg/g and (4) lithium concentrates con-... 

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