Building on work of others was key to lithium-ion batteries
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The development of lithium-ion rechargeable batteries that transformed our way of life was not due to the work of one scientist, as the Royal Swedish Academy of Sciences acknowledged Oct. 9 in awarding this year’s Nobel Prize in Chemistry to three recipients.
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The initial key was a discovery in the late 1970s by John B. Goodenough of the University of Texas at Austin that lithium cobalt oxide could be used as the cathode for a rechargeable battery.
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But it would be up to Akira Yoshino, an honorary fellow at Asahi Kasei Corp., to find the material used in the anode that would eventually lead to the first patented lithium-ion rechargeable battery.
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Yoshino, 71, initially focused on using polyacetylene as the material for the anode as it easily releases and gathers electrons, an important quality that allowed for repeated discharging and recharging of electricity.
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But in 1982, he still faced problems finding the proper material for the cathode. As he was cleaning up his research lab late that year, he happened to come across an article written by Goodenough about using lithium cobalt oxide as a cathode.
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Yoshino quickly realized that battery safety would improve dramatically because lithium would take the form of ions rather than a metal.
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From early in 1983, Yoshino began using lithium cobalt oxide in experimental batteries and found that discharging and recharging of electricity occurred smoothly.
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But one difficulty Yoshino faced while trying to create a compact battery was that polyacetylene took up too much volume. He then considered using a carbon material because it was similar in molecular structure to polyacetylene but smaller in volume.
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Yoshino was also helped by his affiliation with Asahi Kasei. Another research team in the company was looking into developing special carbon materials. Yoshino asked the team if he could use the materials for his experiments. That led to the development of a battery about one-third the size of the one made with polyacetylene.
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The patent for the rechargeable battery with lithium cobalt oxide as the cathode and a carbon material as the anode was applied for in 1985. It would form the basis for the lithium-ion rechargeable batteries that are used in a wide range of products today.
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But, Goodenough himself was lucky enough to be working with another Japanese scientist when he discovered his breakthrough cathode.
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He had just moved to Oxford University in England after the oil shock. He focused his research on development of new energy sources and batteries. He turned to an old acquaintance, Koichi Mizushima, who was then a lecturer at the University of Tokyo. Mizushima is now an executive fellow at Toshiba Corp.
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Goodenough needed Mizushima’s help in developing a cathode for a rechargeable battery.
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They focused on lithium because in the 1970s Stanley Whittingham, the third recipient of this year’s Nobel Prize in Chemistry, had come up with an idea for using metallic lithium for a rechargeable battery. But metallic lithium is prone to causing fires or exploding.
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Initially, sulphide rather than the metal itself was used to increase the safety of the material. But, in 1978, when Goodenough and Mizushima were experimenting with a sulphide, an explosion occurred at their lab, forcing them to give up on the substance.
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They turned to oxides instead and tried various combinations with different materials.
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In autumn 1978, they hit upon lithium cobalt oxide and found it could generate a larger amount of electricity.
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They published an article in 1980 about the possibility of using lithium cobalt oxide as the cathode for the rechargeable battery.
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Mizushima released a statement on Oct. 9 in which he said he was happy to hear that Goodenough had been awarded the Nobel Prize and that he was “deeply honored to have been part of joint research” that led to commercialization of the lithium-ion battery.
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While Goodenough and Yoshino came up with the fundamental ideas for the cathode and anode, the lithium-ion battery technology now used today would not exist were in not for the work of others.
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In 1991, Sony Corp. was the first to use the lithium-ion battery name as it used the battery in mobile phones and later video cameras. A research team led by Yoshio Nishi was responsible for the research and development that led to the commercialization of the battery.
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