BATTERY TECHNOLOGY

 

Batteries are Everyday Objects that we take for granted

        

Not entirely clear what batteries include. Definition – “a device that converts stored chemical or physical energy directly into electricity”.  Probably includes fuel cells, maybe solar cells,…. However whatever they are :-

·           Most people are not interested in what goes on in a battery.

·           Batteries vital for life as we know it.  Phones, computers, cars, clocks, remote controls, torches, hearing aids. What would life be like without them?        

Global demand to climb 4.8% annually through 2014

SLIDE

Chart of World Revenues by battery type  - 2010?

SLIDE

History of Batteries

1748 - Benjamin Franklin first coined the term "battery" to describe an array of charged glass plates.

1780 to 1786 - Luigi Galvani (1737-1798) (Bologna) demonstrated the electrical basis of nerve impulses using static electricity to cause muscles to twitch. In another experiment, Galvani also caused muscular contraction by touching the exposed muscle of one frog with the nerve of another and thus established for the first time that bioelectric forces exist within living tissue. Galvani believed animal electricity was a life force.

1800 Alessandro Volta(1745-1827) invented the Voltaic Pile and discovered the first practical method of generating electricity. Alessandro Volta, a professor of physics (Pavia) , was not convinced by Galvani's theory and demonstrated that the electricity did not come from the animal tissue but was generated by the contact of different metals, brass and iron, in a moist environment. (eg his tongue)

The Voltaic Pile constructed of alternating discs of zinc and copper with pieces of cardboard soaked in brine between the metals produced a reliable, steady current of electricity and was the first "wet cell battery"

1807 Humphry Davy constructed the largest battery ever built at the time, with over 250 cells, and passed a strong electric current through solutions of various compounds suspected of containing undiscovered elements. He isolated  Potassium, Sodium, Calcium, Strontium, Barium, and Magnesium. The following year Davy used his batteries to create an arc lamp which he demonstrated to the Royal Society.

1836 John F. Daniell and Englishman, invented a cell that used two electrolytes: copper sulfate and zinc sulfate with copper and zinc electrodes. The Daniell Cell lasted longer then the Volta cell which could not deliver an electrical current for a long period of time.. This battery, which produced about 1.1 volts, was used to power objects such as telegraphs, telephones, and doorbells, remained popular in homes for over 100 years.

1859 Gaston Plante - French inventor, developed the first practical storage battery that could be recharged (secondary battery). His invention was the lead-acid  battery which is still used in cars today.

1866 Georges Leclanche another Frenchman, patented the carbon-zinc wet cell battery. Leclanche's original cell was assembled in a porous pot. The positive electrode consisted of crushed manganese dioxide and carbon. The negative pole was a zinc rod. The cathode was packed into the pot, and a carbon rod was inserted to act as a current collector. The anode or zinc rod and the pot were then immersed in an ammonium chloride solution. The liquid acted as the electrolyte, readily seeping through the porous cup and making contact with the cathode material. Leclanche then further improved his design by substituting the ammonium chloride paste for liquid electrolyte and invented a method of sealing the battery, inventing the first dry cell, an improved design that was now transportable.

1901 Thomas  Edison invented the alkaline storage battery. Thomas Edison's cell had iron as the anode material (-) and nickel oxide as the cathode material (+). Edison planned to use his battery in electric cars but in the 10 years it took to develop it, gasoline had taken over.

1949 Lewis Urry working for the Eveready Battery Co. developed the Alkaline-Manganese battery which lasted five to eight times as long as zinc-carbon cells, and forms the basis for todays alkaline batteries such as Duracell.

1970’s Stanley Whittingham, first proposed the use of lithium. Whittingham used titanium sulfide as the cathode and lithium metal as the anode. These were primary cells but were unreliable and unstable but showed the possibilities of lithium as an efficient battery material. Lithium batteries in which the anode is made from metallic lithium pose safety issues.

1979, John Goodenough demonstrated a rechargeable cell with high cell voltage in the 4V range using lithium cobalt oxide (LiCoO2) as the positive electrode and lithium metal as the negative electrode. LiCoO2 is a stable positive electrode material which acts as a donor of lithium ions, which means that it can be used with a negative electrode material other than lithium metal. By enabling the use of stable and easy-to-handle negative electrode materials, LiCoO2 opened a whole new range of possibilities for novel rechargeable battery systems.

1981, Bell Labs developed a workable graphite anode to provide an alternative to the lithium metal battery.

1983, Goodenough, and coworkers identified manganese oxide as a cathode material. This showed great promise, given its low-cost, good electronic and lithium ion conductivity

1985, Akira Yoshino assembled a prototype cell using carbon as the anode and lithium cobalt oxide (LiCoO2) as the anode  By using an anode material without metallic lithium, safety was dramatically improved  This was the birth of the current lithium-ion battery.

1991, Sony and Asahi Kasei released the first commercial lithium-ion battery.

2002, Yet-Ming Chiang and his group at MIT showed a substantial improvement in the performance of lithium batteries by boosting the material's conductivity by doping it with aluminum, niobium and zirconium

2004, Chiang again increased performance by utilizing iron phosphate particles of less than 100 nanometers in diameter. This decreased particle density almost one hundredfold, increased the cathode's surface area and improved capacity and performance.

 

Much dispute about patents

 

How do batteries work?

SLIDE

Remember the volta experiment with different metals on the tongue.

 

LEMON BATTERY

Chemistry meets physics

Chemistry and Physics were originally housed under the “Natural Philosophy” umbrella. However as science understanding progressed different disciplines with an artificial boundary evolved and two distinct disciplines evolved.  Batteries demonstrate well that nature has no such boundaries.

 

Making a battery – experiment with lemons and nails

 

Battery Characteristics

SLIDE

Different Types of battery and their characteristics

 

Alkaline Batteries

Alkaline batteries, are little more than an enhancement of 19th Century carbon-zinc technology. The biggest change in chemistry is an alteration to the chemical mix in the electrolyte that makes it more alkaline This change helps to increase storage density and shelf life of the cells.

The construction (as opposed to chemistry) of alkaline cells differs significantly from ordinary carbon-zinc cells, however. Alkaline cells are effectively turned inside-out. The shell of the alkaline battery is nothing more than that–a protective shell–and it does not play a part in the overall chemical reaction. The anode of the cell is a gelled mixture of powered zinc combined with the electrolyte (itself a mixture of potassium hydroxide–a strong alkaline-and water), and the combination is linked to the negative terminal of the cell by a brass spike running up the middle of the cell. The cathode, a mixture of carbon and manganese dioxide, surrounds the anode and electrolyte, separated by a layer of non-woven fabric such as polyester.

Lead Acid Batteries

Because the electrolyte takes part in the charge-discharge reaction, this battery has one major advantage over other chemistries. It is relatively simple to determine the state of charge by merely measuring the SG of the electrolyte, the S.G. falling as the battery discharges. When used in diesel-electric submarines, the S.G. was regularly measured and written on a blackboard in the control room to indicate how much longer the boat could remain submerged. Not relevant today  - gel electrolyte

 

Nickel–metal hydride battery

Type of rechargeable battery similar to the nickel–cadmium cell. The NiMH battery uses a hydrogen-absorbing alloy for the negative electrode instead of cadmium. The positive electrode is nickel oxyhydroxide (NiOOH). A NiMH battery can have two to three times the capacity of an equivalent size nickel–cadmium battery. The energy density of a NiMH cell is similar to that of a lithium-ion cell, but the rate of self-discharge is higher. This means that a stored NiMH battery will lose charge more quickly.

 

Lithium

SLIDE

 

Lithium Ion

SLIDE

 

Silver Oxide

SLIDE

 

Zinc air cells (hearing aid)

SLIDE

 

Unusual Types

A sodium–sulfur battery or liquid metal battery is a type of molten metal battery[1] constructed from sodium (Na) and sulfur (S). This type of battery has a

•         high energy density,

•         high efficiency of charge/discharge (89–92%) and

•         long cycle life, and is

•         fabricated from inexpensive materials.

•         operating temperatures of 300 to 350 °C and

•         highly corrosive nature of the sodium polysulfides,  primarily suitable for large-scale non-mobile applications such as grid energy storage. – eg Windfarms

 

Vanadium Redox

How big a battery is required to supply MW hours? Vanadium Redox Battery system allows this to be done in a reasonable space. According to VRB Power Systems, Vancouver BC, liquid storage of 400,000 liters of electrolyte is required. Then an additional 10 to 15% area of space is required to hold the battery cell stacks and the power conversion system to convert from DC power to AC power. The system is based on energy storage in two different electrolyte solutions which are made up of dilute sulphuric acid and emulsified vanadium particles. The particles are stored in two tanks, one for the positive electrolyte, and one for the negative electrolyte. The two liquids are pumped to opposite sides of half-cells separated by a membrane. In large installations, the cell stacks are rated at 50 kW each. Based on the direction of current flow, the cells either produce power, or use applied power to recharge the electrolytes.

 

Nuclear Batteries

The battery's power comes from promethium 147 which emits low-energy beta particles (electrons). Other atomic batteries have attempted to turn beta particles directly into electric current, but they have often run into trouble because the particles damage the current-yielding parts of the battery. The Kidde-Elgin battery sidesteps this difficulty by mixing the promethium 147 with a phosphor (light-giving substance) and enclosing the mixture in transparent plastic. Electrons from the Pm-147 make the phosphor glow, and its light is turned into electricity by a photoelectric surface of silicon on each side of the plastic wafer. No electrons escape from the plastic, and so the silicon is not damaged.  Low power mw range, Space and defence uses.

 

Not all batteries are the same

Chart of Specific Energy v Specific Power for different battery types.

SLIDE

Chart Comparison of Battery Energy

SLIDE

Practical tips with batteries

SLIDE