A short and deliberately selective history of technological advances in the world of energy storage over the past 25 years.

An overview of the past quarter century of battery development is almost impossible to give without taking sides over which chemistry should be promoted or which will achieve dominance in the next 25 years.

Talk about “horses for courses” — energy storage suited to its application — has always missed the point. The battery of choice for the car — with some billion running around the world as we speak — is the lead acid battery.

Despite the arrival of competing chemistries many forecasts suggest that the number of automotive lead batteries driving around the world will reach 2 billion by 2035.

The death of the lead battery com-munity has been predicted for — at least — the last 40 years. David Wil-son, a former head of the Interna-tional Lead Association, says that the death of the lead acid battery had been anticipated from his very first years in the industry.

Irrespective of their strength as a commercial product, lead batteries now compete in a world where other chemistries dominate — and rightly so.

Although NiMH was part of the brave new world that seemed to sup-plant lead batteries in the 1990s, ad-vances in its chemistry proved limited.

Meanwhile, lithium ion has gradual-ly advanced up the energy chain from being the powerhouse in laptop com-puters and the earliest mobile phones to claims by car maker Tesla that they will power the cars of the future. (That is before fuel cells make the next tech-nology leap, says Tesla founder Elon Musk.)

But as this technological history of batteries shows, the world of in-novation continues to throw up new opportunities and challenges for all chemistries.

A QUARTER CENTURY OF BATTERY DEVELOPMENT

The 1990s

New battery technologies enable the development of cordless and portable devices (power tools, mobile phones, lap-top computers, PDAs, digital cameras, personal care items) and consequently boost demand for batteries. Increased volumes bring prices down, reinforcing demand.

Attempts at using lead batteries for electric vehicles with General Motor’s EV1 programme, that eventually failed, showed there was a potential for EVs. Ford’s Ecostar programme, a fleet of more than 100 cars, looked at sodium sulfur batteries — then a very novel battery — in the early 1990s, but eventually diverted research into fuel cells.

Meanwhile, great strides were being made in lead battery manufacturing, with everything from better formation systems to better paste making arriving on the scene.

1990 – Commercialization of the NiMH bat-tery after a relatively short period of development of only four years is helped by the fact that the new NiMH cells could be made using the same equipment that had been used to man-ufacture NiCad cells.

The first volume introduction of lith-ium secondary cells for consumer ap-plications after more than 10 years of development.

1991 – Welsh firm Atraverda founded to com-mercialize bipolar lead acid batteries us-ing Ebonex ceramic — a metallic-type conductor having a conductivity compa-rable to carbon but with superior oxida-tion resistance. The crystal structure of the titanium suboxides makes for a com-bination of corrosion resistance, oxida-tion resistance and electrical conductivity.

Commercialization of the product is troubled by management conflicts and the advantages of the battery such as reduced levels of lead are hampered by difficulties in putting them onto a commercial production line.

1995 – English stuntman, swimming professional and inventor Trevor Baylis devises a method of producing a practical long-lasting supply of electricity from a wind-up spring. Using springs to generate electricity is nothing new, but before Baylis’ invention, the energy tended to be produced for only a short duration. Baylis devised a clockwork battery by connecting the spring through a gear box, which releases the energy slowly to a dynamo. This was later adapted to feed the energy into rechargeable cells.

Trevor Baylis

1991 – Carbon nanotubes, or Buckytubes, are discovered by the Japanese elec-tron microscopist Sumio Iijima, who was studying the material deposited on the cathode during the arc-evapo-ration synthesis of fullerenes. Bucky-tubes can exhibit either semiconduct-ing or metallic properties.

They also have the intrinsic charac-teristics desired in the nanomaterials used as electrodes in batteries and ca-pacitors: a tremendously high surface area (~1000 m2/g), good electrical conductivity, and very importantly, a linear geometry which makes their surface highly accessible to the elec-trolyte. Buckytubes have the highest reversible capacity of any carbon ma-terial that can be used in lithium ion batteries.

1991 – Swiss scientist Michael Grätzel and co-workers at the Swiss Federal Insti-tute of Technology patent the Grätzel solar cell, a regenerative battery de-pending for its operation on a photo-electrochemical process similar to photosynthesis.

1992 – Austria-born Karl Kordesch of Can-ada patents the reusable alkaline bat-tery the so-called (RAM) Recharge-able Alkaline Manganese battery. Kordesch holds 150 patents on bat-tery and fuel cell technology.

1993 – John Cooper, working at the Law-rence Livermore Labs, patents the zinc air refuellable battery, using a cell chemistry first demonstrated by Heise and Schumacher in 1932. The battery is charged with an alkaline electrolyte and zinc pellets, which are consumed in the process to form zinc oxide and potassium zincate. Refuel-ling takes about 10 minutes. These short refuelling times, made possible with mechanical charging, are attrac-tive for EV applications. The spent electrolyte is recycled.

1994 – Bellcore patent on Plastic Lithium Ion (PLI) technology granted. Lithium polymer cells with a solid polymer electrolyte. The solid state battery.

1995 – Introduction of the pouch cell made possible by lithium PLI technology.

1995 – Duracell and Intel develops the Smart Battery system for Intelligent Batteries and proposes the specification with its associated SMBus as an industry standard.

1995 – On-cell battery condition indicator or fuel gauge for consumer primary cells introduced by Energizer.

1995 – BMW abandons flywheel energy stor-age after a test technician is killed and two others injured when the contain-ment enclosure weighing 2,000Kg fails to protect them from shrapnel when a high speed rotor fails.

1996 – Researchers Theodore Poehler and Peter Searson at The Johns Hopkins University demonstrate an all-plastic battery using doped polymer, polypyr-role (five-membered ring structured organic molecule, capable of redox re-actions), composite electrodes in place of the conventional electrode materi-als.

1998 – 48MWh Sodium sulfur load-levelling battery delivering 6 MW for eight hours installed by NGK for Tokyo Electric Power Company (TEPCO).

The 2000s

The decade was spent (again) forecasting that lead was dead. The conclusion was reached after a variety of developments, mostly the rise of fuel cells and the application of NiMH in electric vehicles. Towards the end of the decade, however, vast insertions of US government money, mainly into lithium ion chemistry, caused a speculative investment spike in electric vehicles which was to end mostly in tears in the years to come.

2000 – Indian chemist Sukant Tripathy, work-ing at the University of Massachusetts, demonstrates polymer photovoltaic cells for making flexible solar panels using nanotechnology.

2001 – Russian scientists’ work on develop-ing the lead carbon battery begins the commercialization and eventual creation of Axion Power. The PbC is similar to a standard lead acid battery but uses the standard lead acid battery positive electrode and a super-capaci-tor negative electrode.

The specific type of activated carbon it uses has an extremely high surface area and has been formulated for use in electrochemical applications. During charge and discharge, the positive electrode undergoes the same chemical reaction that occurs in a conventional lead acid battery.

The main difference in the PbC bat-tery is the replacement of the lead nega-tive electrode with an activated carbon electrode that, being a supercap, does not undergo a chemical reaction at all.

2001 – John Smalley, working at the US Department of Energy’s Brookhaven National Lab, announces the development of nanowires, organic molecules called oligophenylenevinylene (OPV). These molecules are essentially “chains” of repeating links made up of carbon and hydrogen atoms that allow a very fast rate of electron transfer down the chain acting as extremely fine, low resistance wires only one molecule in diameter.

John Smalley

2002 – Various patents are filed on nanomate-rials used in lithium and other batter-ies to achieve increases in charge and discharge rates of 10 to 100 times.

2002 – Commercialization of solid state lith-ium polymer thin film batteries based on patents from ORNL.

2003 – Teeters, Korzhova and Fisher, working at the University of Tulsa in the USA, patent the nanobattery so small they can fit 60 of them across the width of a human hair.

2003 – RWE, the German multi-utilities group and new owners of National Power (now renamed Innogy), pull the plug on the Regenesys battery project before the battery is completed despite spending $250 million over 14 years.

2003  –The world’s biggest battery was con-nected to provide emergency power to Fairbanks, Alaska’s second-largest city. Without power lines between Alaska and the rest of the US, the state is an electrical island.

The $35 million rechargeable battery contains 13,760 large Nickel-Cadmi-um cells in FOUR strings weighing a total of 1,300 tonnes and cover-ing 2,000 square metres. The battery can provide 40MW of power for up to seven minutes while diesel backup generators are started.

2003 – Finnish metallurgist Rainer Partanen patents the rechargeable aluminium air battery using nanotechnology to achieve very high energy densities.

2004 – Toshiba demonstrates a direct metha-nol fuel cell (DMFC) small enough to power mobile phones. The fuel cell provides an output of 100mW from a cell measuring 22x56x4.5mm. A single charge of 2cc of methanol will power an MP3 player for 20 hours.

2003 – Worldwide battery sales — a snapshot • Total world sales value $48 billion. • Sales value of small rechargeable batteries – $7.6 billion. • More than 110 million automotive lead acid batteries were manufactured for more than 650 million vehicles on the world’s roads. 81% of sales were to the replacement market. • Sales value of industrial batteries for traction and standby power applications – $14 billion. • 500,000 electric bicycles per year sold in China. • The HEV/EV battery market is expected to grow at an AAGR of more than 50% to nearly $250 million in 2008. • Total battery demand expected to exceed $60 billion by 2006 and $65 billion by 2008.

2005 – CSIRO researchers David Rand and Lan Lam awarded patent for the Ul-traBattery. This is a hybrid device that combines ultracapacitor technology with lead acid battery technology in a single cell with a common electrolyte.

Physically, UltraBattery has a single positive electrode and a twin nega-tive electrode – one part carbon, one part lead, in a common electrolyte. Together these make up the negative electrode of the UltraBattery unit, but specifically the carbon is the electrode of the capacitor and lead is the elec-trode of the lead-acid cell. The sin-gle positive electrode (lead oxide) is typical of all lead acid batteries and is common to the lead acid cell and the ultracapacitor.

This technology (specifically the ad-dition of the carbon electrode) gives UltraBattery different performance characteristics from conventional VRLA batteries. In particular Ultra- Battery technology suffers signifi-cantly less from the development of permanent (or hard) sulfation on the negative battery electrode – a problem commonly exhibited in conventional lead acid batteries.

2005 – Korean bioengineer Ki Bang Lee, working at Singapore’s Institute of Bioengineering and Nanotechnology, develops a paper battery powered by urine which can be used as a simple, cheap and disposable power source for home health tests for diabetes and other ailments.

2005 – US firm Firefly Energy received first of several US patents for its carbon-graphite foam lead acid battery technology based on a material sciences innovation dis-covered by Caterpillar Inc. Unlike con-ventional lead acid batteries, this lasts longer, is smaller, weighs less because of the reduction of lead, sheds heat more effectively and can be re-charged more quickly. Unfortunately Firefly is unable to commercialize the technology.

2005 – Masaharu Satoh, working at NEC in Japan, reveals details of a high C rate Organic Radical Battery (ORB). This is a low-capacity battery which runs for only a short period but can be charged and discharged at 100C.

2005 – Fraser Armstrong, working at Oxford University, demonstrates the proto-type of a biofuel cell which uses as fuel the small amounts of free hydrogen available in the atmosphere and an enzyme to promote oxidation, rather than an expensive catalyst.

2006 – Researchers at MIT’s Laboratory for Electromagnetic and Electronic Sys-tems (LEES), John Kassakian, Joel Schindall and Riccardo Signorelli, suc-ceeds in growing straight single wall nanotubes (SWNT) with diameters varying from 0.7 to 2 nanometres and lengths of several tens of microns (one 30,000th the diameter of a hu-man hair and 100,000 times as long as they are wide) which they use to make enhanced double layer capacitors with major performance improvements.

2007 – Apple launches the iPhone, a revolu-tionary, Internet-capable smart phone. With the idea of a rechargeable bat-tery that is not removable — capable of lasting the life of the phone — this is to set the benchmark for battery management systems and batteries for the next decade and beyond.

2007 – Sony announces a Sugar Battery, a Biofuel Cell using glucose as fuel with enzymes for catalysts, developed by Tsuyonobu Hatazawa and Professor Kenji Kano from Kyoto University.

It consists of an anode and a cath-ode separated by a proton-conducting membrane. A renewable fuel, such as a sugar, is oxidised by microorganisms at the anode, generating electrons and protons. The protons migrate through the membrane to the cathode while the electrons are transferred to the cathode by an external circuit. The electrons and protons combine with oxygen at the cathode to form water.

2008 – American inventor Lonnie Johnson discovers a breakthrough method of turning heat into electrical energy that he uses in a new form of thermoelec-tric battery.

The 2010s

The 2010s have been characterized by a huge R&D spend in lithium ion battery chemistry.

Investment, mainly from governments and particularly that in the US, that had seemed wasted at the start of the decade, returned to bite the lead acid battery community, which had been suffering from minimal research programmes except for those still coming from ALABC, East Penn, Hammond and Trojan.

Incremental changes in the price point per kWh for lithium versus lead batteries narrowed the competitive gap between the two chemistries.

The sudden arrival of renewable energy in scale in the mid 2010s caught utilities off guard, but meant that grid balancing functions were needed to account for intermittency. The arrival of residential PV electricity began to change business models forever. Lead lost out to lithium, but given the industry is still emerging there is scope for advanced lead batteries to compete.

What lead lost to lithium it made up for in spades with EFB and VRLA batteries throwing off the challenge of pure electric vehicles as they dominate the large and still rapidly growing stop-start market.

2011 – Researchers Yu-Chueh Hung, Wei Ting Hsu and Ting-Yu Lin at the In-stitute of Photonics Technologies at Taiwan’s National University (TNU), working with Ljiljana Fruk at the Centre for Functional Nanostructures at Karlsruhe Institute of Technol-ogy (KIT) in Germany, demonstrates a photo-induced write-once read-many-times (WORM) organic memory de-vice based on DNA biopolymer nano-composite (published in AIP Applied Physics Letters). In other words they shows that DNA can be used as a data storage medium.

2012 – Following on the previous year’s research in Taiwan’s TNU and Karlsruhe’s KIT, Harvard researchers George Church and Sri Kosuri takes a major step towards producing a practical DNA Data Storage device by successfully storing 700 terabytes of data (5.5 petabytes) in a single gram of DNA.

2012 – Researchers Donald Sadoway and David Bradwell, working at MIT, pro-duce working prototypes of a liquid metal battery using magnesium-anti-mony molten salts.

2013 – Hammond releases K2 range of ex-panders offering step change in lead acid battery performance, particularly in terms of cyclability in partial state of charge and offering performance benefits that can be adjusted to vary-ing temperature ranges and demands.

2014 – Aqua Metals demonstrates novel way of recycling lead acid batteries without the use of smelting. Commercializa-tion of the technology continues with launch of new factory in 2016.