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Journal of Materials Chemistry A Paper batteries (VRB) have been considered as promising candidates for EES systems in addition to LIBs.2,3 NaS has an energy cost of 438–477 $ kW h1 and the energy cost of VRB is higher. The energy cost of the saltwater battery with 5 M NaCl is estimated to be only 189 $ kW h1; while zinc–air batteries, the next cheapest candidate, is priced at 310 $ kW h1. The saltwater batteries are remarkably low-cost in terms of both energy and power production. In addition, the working potential and energy density (up to 423 W h kg1 with 6 M saltwater) of the saltwater battery can be tuned by the salt concentration for different applications. Conclusions We have developed a new type of rechargeable saltwater battery, which is distinct in that saltwater acts as the energy source, not just the electrolyte. It is operated by evolution/reduction reac- tions of gaseous phases in saltwater at the cathode, along with reduction/oxidation reactions of the dissolved Na+ ions at the anode. Galvanostatic charge–discharge and CV measurements indicated that the OER mainly occurs during the charge process; however, given the monotonic decrease of the Cl concentration in saltwater with charging time, the possibility of the CER cannot be excluded. We are currently investigating the evolved O2 and Cl2 gases and their ratio during charging, using advanced analytical tools such as customised cells equipped with a differential electrochemical mass spectrometer. The full- cell saltwater battery (hard carbon|5 M saltwater) exhibited a high discharge capacity with a stable capacity retention and a high coulombic efficiency of 98% over 50 cycles. As a concep- tually simple energy storage device, this battery using the eco- friendly, low-cost saltwater as the active material will be an optimal building block for large-scale stationary EES applications. Experimental Preparation of the saltwater battery For the catholyte, 60 mL saltwater was prepared by dissolving NaCl (Sigma Aldrich) in deionised water at various concentra- tions of 0.4–5 M. For the cathode current collector, a Ti mesh (Wooilmetal Corporation) and a sheet of hydrophilic carbon paper (Fuel Cell store) were used. A 0.8 mm-thick NASICON-type solid electrolyte (Na3Zr2Si2PO12) with a diameter of 16 mm was prepared according to previous studies.16,19–21 For the anode compartment, the solid electrolyte was mounted on the open- structured anode top holder and then sealed with the anode bottom holder, which contained an organic electrolyte of 1 M NaCF3SO3 (Sigma Aldrich) in TEGDME (Sigma Aldrich) and a Ni tap (anodic current collector, Solbrain LTK) attached to the Na metal or hard carbon electrode. The assembly process was carried out in a glovebox under a high-purity Ar atmosphere (O2 and H2O less than 1 ppm). The hard carbon electrode was prepared from a slurry of hard carbon (MeadWestvaco Corpo- ration), carbon black Super-P (TIMCAL), and polyvinylidene uoride (PVdF, Sigma Aldrich) at a weight ratio of 80 : 10 : 10. The slurry was coated on Cu foil (14 mm thick) with a doctor- 7212 | J. Mater. Chem. A, 2016, 4, 7207–7213 blade, and dried in a convection oven. Finally, the electrode was roll-pressed and dried in a vacuum oven. The loading level of hard carbon was approximately 2.44 mg cm2. The assembled cells which consisted of the Ni tap|anode|organic electrolyte| NASICON|saltwater|carbon paper|Ti mesh were immersed in saltwater for electrochemical tests. Characterisation and electrochemical measurements The phase identication was carried out by using an XRD (D/Max, Rigaku apparatus) equipped with a Cu Ka X-ray source (l 1⁄4 1.5406 A ̊). X-ray photoelectron spectroscopy (XPS, Mg Ka, Thermo Fisher) and contact angle measurements (Phoenix 300, SEO) were performed to examine the surface chemistry and wettability of carbon paper, respectively. The surface morphology and microstructure were observed by using a SEM (verios 460, FEI company) equipped with an EDS (Bruker). In order to check Na+ insertion in the anode side aer charging, the cells were carefully disassembled and the electrode was rinsed with a TEGDME solvent and then dried in a vacuum chamber. The Cl concentration in saltwater was determined by using an ion chromatography system (Dionex ICS 3000). The density of the solid electrolyte was measured by using a gas displacement pycnometry system (AccuPyc 1340, Micromeritics Instrument Corp.). The ionic conductivities of the solid elec- trolyte and saltwater were evaluated by electrochemical impedance spectroscopy (EIS, BioLogic) in the frequency range of 100 mHz to 7 MHz and a voltage amplitude of 14.2 mV. Cyclic voltammetry (CV, BioLogic) was performed using a three-electrode cell and the CV curves were recorded at a scan rate of 10 mV s1. A carbon paper electrode was used as the working electrode, and an Ag/AgCl electrode (3 M NaCl, 0.197 V vs. SHE) and a Pt wire were used as the reference and counter electrodes, respectively. The electrochemical properties of salt- water batteries were measured by using a battery cycler (WBCS 3000, Wonatech) at room temperature. The batteries were gal- vanostatically charged and discharged at current rates of 0.01– 0.5 mA cm2. The hard carbon anode was examined at a current rate of 0.025 mA cm2 in the voltage window of 0–2 V vs. Na+/Na over 5 cycles. The full-cell saltwater batteries were tested at a current rate of 0.025 mA cm2 with a capacity cut-off of 300 mA h ghard carbon1 upon charging, and a voltage cut-off of 0.5 V upon discharging. Acknowledgements This work was supported by the 2015 Research Fund (1.150034.01) of the UNIST (Ulsan National Institute of Science and Technology) and the Energy Efficiency & Resources Core Technology Program of the Korea Institute of Energy Tech- nology Evaluation and Planning (KETEP) granted nancial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20142020104190). Notes and references 1 M. Z. Jacobson, Energy Environ. Sci., 2009, 2, 148–173. This journal is © The Royal Society of Chemistry 2016PDF Image | Saltwater as the energy source for low-cost batteries
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Product and Development Focus for Infinity Turbine
ORC Waste Heat Turbine and ORC System Build Plans: All turbine plans are $10,000 each. This allows you to build a system and then consider licensing for production after you have completed and tested a unit.Redox Flow Battery Technology: With the advent of the new USA tax credits for producing and selling batteries ($35/kW) we are focussing on a simple flow battery using shipping containers as the modular electrolyte storage units with tax credits up to $140,000 per system. Our main focus is on the salt battery. This battery can be used for both thermal and electrical storage applications. We call it the Cogeneration Battery or Cogen Battery. One project is converting salt (brine) based water conditioners to simultaneously produce power. In addition, there are many opportunities to extract Lithium from brine (salt lakes, groundwater, and producer water).Salt water or brine are huge sources for lithium. Most of the worlds lithium is acquired from a brine source. It's even in seawater in a low concentration. Brine is also a byproduct of huge powerplants, which can now use that as an electrolyte and a huge flow battery (which allows storage at the source).We welcome any business and equipment inquiries, as well as licensing our turbines for manufacturing.CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)