IT S ELEMENTARY: HUMAN EXISTENCE AND THE CHEMICAL ELEMENTS PART 2 SC 204 OCTOBER 2, 2015 JOHN BUSH

Transcription

1 IT S ELEMENTARY: HUMAN EXISTENCE AND THE CHEMICAL ELEMENTS PART 2 SC 204 OCTOBER 2, 2015 JOHN BUSH

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3 The Periodic Table ranks as one of the most fruitful and unifying ideas in the whole of modern science, comparable perhaps with Darwin s theory of evolution by natural selection Eric R. Scerri The Periodic Table: Its Story and Its Significance Oxford University Press, 2007

4 SPRING 2015 TOPICS Elements for poisoners-criminal, suicidal, military, judicial Elements for communication at a distance from the telegraph to the cellphone The periodic table history, structure, categories: non-metals, inert gases, metals, semi-metals, rare earths,

5 ELEMENTS FOR CRIMINAL POISONERS

6 THE ELEMENTS OF MILITARY POISONS

7 PARACELSUS All things are poison and nothing is without poison; only the dose makes a thing not a poison (1538)

8 ELEMENTS: THE METALS

9 USEFUL CONCEPTS Classical elements: earth, air, fire, water Chemical elements: un-decomposable substances-- H, O, N, C Chemical compounds: substances formed from the elements by chemical reactions Water Carbon dioxide Cane sugar Table salt

10 SOME MORE CONCEPTS Atoms: smallest particles of elementary substances H, O, C Molecules: chemically bonded atoms H 2, O 2, H 2 O, CO 2, C 12 H 22 O 11, HCl Ions: electrically charged atoms or groups of chemically bonded atoms: H +, Na +, Cl -, CO -2 3, SO -2 4, V 10 O -6 28, AlCl - 4 Chemical bonds: Ionic: NaCl = Na +. Cl - (s) Shared electron: H 2 O = H-O-H

11 CLASS SUGGESTIONS OF TOPICS Medications as correction for chemical imbalance in the body or particularly the brain Cooking Forensics Pharmacology in medicine Chemicals in common household items (such as cleaning supplies) Chemicals in processed foods and how they affect our health Chemistry of blood Lighting/lasers Changes in energy involved in transportation (propulsion of cars, ships, rockets/missiles, etc.) Batteries Simple physics how things work

12 THE ELEMENTS OF BATTERIES

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14 OUTLINE What is a battery anyway? A little bit about electricity Some battery fundamentals Primary batteries Rechargeable batteries

15 WHAT IS A BATTERY? A device that converts the potential chemical energy stored in a galvanic cell into heat and/or work by creating an electric current Two or more galvanic cells connected with one another by conductors of electricity A source of and sink for electrons when part of a complete electric circuit A source of low voltage direct current A means of interconverting electrical energy and potential chemical energy as needed (secondary battery) A self contained portable supply of electric power A means of storing electrical energy for use when needed

16 ELECTRIC CIRCUIT Electric current is the flow of electric charge Electric current requires the movement of charge carriers Electrons negative charge Ions either positive or negative charges For a current to flow the carriers of oppositely signed charges must be able to neutralize one another (form a complete circuit) For a current to flow there must be a medium that permits the movement the charge carriers (a conductor) For a current to flow there must be a force that generates the motion of the charge carriers

17 COULOMB S LAW The magnitude of the electrostatic force of interaction between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them. If the two charges have the same sign, the electrostatic force between them is repulsive; if they have different signs, the force between them is attractive. Force = k Iq 1 q 2 I r 2

18 OHM S LAW v=ir

19 JOULE-LENZ LAW The passage of electric current through a resistor generates heat Heat = i 2 Rt Applies whether the charge carriers are electrons or ions

20 AN ELECTROCHEMICAL CELL REDOX REACTION- ACTIVE MATERIALS ELECTRODES SEPARATOR ELECTROLYTE EXTERNAL CONDUCTOR

21 WHAT DOES A PRIMARY BATTERY DO? Provides electrons to the part of the complete circuit external to the battery with sufficient energy to cause a current to flow Derives the energy from the chemical reactions of active materials during discharge Provides positive ions to the part of the circuit internal to the battery, overcoming internal resistance Ohm s law applies Joule-Lenz law applies Provides sufficient force (voltage) to accomplish the external circuit s task

22 THE DRY CELL

23 THE ALKALINE MANGANESE CELL

24 ALKALINE CELL CORROSION

25 USEFUL PRIMARY BATTERIES SOME NECESSARY PROPERTIES Voltage and current meet the requirements of the intended use Capacity and life meet the requirements of the intended use Shape and size meet the requirements of the intended use Safety meets the requirements of the intended use Costs of materials, manufacture and maintenance meet the requirements of the intended user

26 VARIETIES OF PRIMARY BATTERIES Atbatt.com: over 4000 types of batteries Consumer batteries: alkaline manganese, lithium, silver oxide, mercuric oxide Industrial and military batteries tailored to applications

27 PRIMARY BATTERIES ACTIVE MATERIALS Anodes: lithium, zinc, cadmium, mercury, magnesium, aluminum Cathodes: nickel, iron, cobalt, manganese, sulfur, silver, oxygen, iodine

28 PRIMARY BATTERY ELEMENTS RED=ANODE GREEN = CATHODE

29 THE ALKALINE MANGANESE CELL

30 ZINC ZINC OXIDE

31 ZINC (Zn) Atomic number 30 Isotopes 64, 66, 67, 68, 70 Isolated in antiquity Abundance 27 th in the crust (780 ppm) Uses: Metal: rust-preventing coatings, die cast metal parts, alloys-brass, primary batteries; Oxide: paints, rubber, sun-blockers

32 Metal MANGANESE Mn(II) chloride Mn(IV)oxide MnO 2 Mn(VII) salt Potassium permanganate solution)

33 MANGANESE (Mn) Atomic number 25; Isotope 55 Abundance : 12 th in the crust (1100 ppm) Element isolated in 1744 Uses: Metal: alloys-stainless steel, corrosionresistant aluminum; Oxide: primary batteries, pigments; Nutrition: essential trace element

34 IMPLANTABLE PACEMAKER AND BATTERY

35 PACEMAKER BATTERIES Since 1972 the active materials have been metallic lithium and an iodine-organic complex Some characteristics Adequate voltage with slow decay in use High internal resistance severely limits available current Long useful life: high energy density, low self discharge No leakage/rupture Not rechargeable

36 LITHIUM LITHIUM (FLOATING ON OIL) LITHIUM (IN DRY NITROGEN) LITHIUM (IN MOIST AIR)

37 LITHIUM (Li) Atomic number 3 Isotopes 6, 7 Abundance 33 rd in the crust 17ppm Discovered 1817 isolated 1821 Uses: Metal: batteries, military propellants, meth synthesis; Salts: batteries, ceramics/glass, medication, grease, aluminum production, optics, hydrogen bombs

38 CONSUMER LITHIUM BATTERIES A family of primary batteries with lithium metal anodes Cathode materials: manganese dioxide, carbon monofluoride, iron disulfide, thionyl chloride, sulfur dioxide, silver oxide/vanadium pentoxide, iodine/polyvinylpyridine Electrolytes: no water! lithium salts dissolved in liquids, solid lithium iodide

39 IODINE IODINE CRYSTALS IODINE VAPOR

40 IODINE (I) Atomic Number 53 Isotope 127 Abundance 63 rd in crust (0.49 ppm) Discovered 1811 Current uses: X-ray radio-contrast agents, disinfectants, essential trace nutrient

41 APPLICATIONS OF RECHARGEABLE BATTERIES Provide a way to make the wall socket portable Portable electric powered appliances Portable electronic devices Electric powered vehicles Provide a way to assure that demand for and supply of electric power is always equal Provide a way to disconnect from suppliers and other users of electric power

42 CLASSIC ELECTRIC GRID WITH STORAGE

43 FUTURE ELECTRIC GRID Adds intermittent power generation Solar Wind Tidal Requires a way to match varying supply with varying demand time shifting demand and supply Solution: energy storage Centralized? Distributed?

44 SUPPLY/DEMAND SMOOTHING

45 RECHARGEABLE BATTERIES LEAD ACID BATTERY

46 RECHARGEABLE BATTERIES During discharge they act like a primary battery consuming active materials to provide direct electric current to an external load During recharge an external source of direct electric current restores the active materials that were consumed on discharge During standby bad things can happen self discharge, internal short circuits, corrosion and leakage,

47 USEFUL RECHARGEABLE BATTERIES SOME NECESSARY PROPERTIES Voltage and current meet the requirements of the intended use Capacity and CYCLE life meet the requirements of the intended use Shape and size meet the requirements of the intended use Safety meets the requirements of the intended use Costs of materials, manufacture and maintenance meet the requirements of the intended user

48 WHAT DETERMINES THE BATTERY PROPERTIES? Voltage and current : maximum possible are determined by the chemical nature of the electrochemically active materials and the design electrolyte, current collector, separator Capacity and life depend on the design and on the rates of charge and discharge in use Safety and cost depend on the costs and properties of the active materials and on the overall design Cycle life is affected by all of these Shape depends primarily on the application

49 CONSTRUCTION COMPONENTS Electrochemically active materials Anode material Cathode material Current collector Electrolyte Separator Container Others depending on design

50 A SECONDARY BATTERY SCHEMATIC

51 WHAT S GOING ON IN THE CELL? Oxidation: a material is oxidized when electrons are removed from it (Cathode) H 2 - -> 2H + + 2e - 4OH - --> O 2 + 2H 2 O+ 4e - Reduction: a material is reduced when electrons are added to it (Anode) 2H 2 O + O 2 + 4e - --> 4OH - 2H + + 2e - --> H 2 Overall: Discharge 2H 2 +O 2 2 H 2 O Recharge 2H 2 O 2H 2 + O 2 (electrolysis) Ionic charge carriers in the electrolyte: H + OH - +other salts

52 SECONDARY BATTERIES ACTIVE MATERIALS Anodes: lithium, hydrogen(metal hydrides), cadmium, lead, zinc, vanadium, sodium, potassium, aluminum, magnesium Cathodes: nickel, cobalt, vanadium, iron, manganese, bromine, sulfur, lead

53 SECONDARY BATTERY ELEMENTS

54 SECONDARY LITHIUM BATTERIES ACTIVE MATERIALS Lithium ion batteries Anodes: lithium ions/graphite, graphene, lithium titanate Cathodes: lithium iron phosphate, lithium cobalt oxide, lithium Ni/Mn/Co oxide Lithium metal batteries Anodes: Lithium/silicon-carbon, nanowire carbon, silicon nanowire Cathodes: Sulfur/graphene oxide, sulfur/lithium sulfide, glass coated sulfur

55 COBALT ELEMENTAL COBALT TARGET 14 TH CENTURY CHINESE VASE

56 COBALT (Co) Atomic number 27 Isotope 59 Abundance 32 nd in crust (20 ppm) Identified as an element 1732 Current uses: essential in diet-vitamin B 12, gamma ray source ( 60 Co), pigments, high temperature-resistant alloys, wear-resistant alloys, magnetic alloys, batteries

57 A FLOW BATTERY SCHEMATIC

58 VANADIUM VANADIUM METAL V(II) V(III) V(IV) V(V)

59 VANADIUM (V) Atomic number 23 Isotope 51 Abundance 20 th in crust (190 ppm) Discovered 1801 Isolated 1830 Uses: Metal: vanadium steel, high speed tool steels, titanium alloys; Salts: catalysts, glass, ceramics, batteries

60 VANADIUM FLOW BATTERY

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62 USEFUL RECHARGEABLE BATTERIES SOME NECESSARY PROPERTIES Voltage and current meet the requirements of the intended use Capacity and cycle life meet the requirements of the intended use Shape and size meets the requirements of the intended use Safety meets the requirements of the intended use Costs of materials, manufacture and maintenance meet the requirements of the intended user

63 WHAT DO YOU THINK? With all the science and engineering talent and all the money being applied to battery research and development And with the whole periodic table to draw on How soon will we have the battery that will recharge the world?