After considering thge current state of the market for lithium-ion batteries – they estimate three billion cells are produced per annum for use in consumer, industrial and automotive applications, with a total market value of $18bn – they say the current technology uses “essentially the same chemistry as that invented in Oxford by Goodenough and colleagues in 1980”.
Current lithium ion battery (LIB) electrodes are “monolithic” in that the electrochemically active materials that are used in powder form in the electrodes, and the residual porosity between the powder particles, are constant through the electrode thickness. Despite their known benefits, graded electrodes are not commercially available because a scalable manufacturing technology has not been developed. Recent developments in Oxford aim to enable electrodes to be fabricated using spray deposition that will allow the porosity and other characteristics to be varied in a controlled fashion through the electrode thickness, thus facilitating both better performance of existing battery chemistries and the commercialisation of new battery chemistries.
Oxford’s technology is scalable, allowing LIB manufacturers to spray electrodes from a variety of suspensions. Thin, flexible electrodes (100s nm to 10s µm) can be produced and various nanomaterials can be introduced into the electrode at any point. The spraying process allows the electrodes to be graded in different ways. Recent literature suggested that in theory, a capacity increase of up to 70 percent might be possible over conventional slurry-cast LIBs if graded particle and porosity distributions were available. Improvements in thinness and flexibility fit well with requirements for LIBs in mobile electronics, whilst improved energy density and the possibility of using safer electrolytes suits transport applications.
The underlying technology is the subject of a UK patent application, and they say comparative performance tests against conventionally manufactured LIBs are still being run.
Isis Innovation is inviting companies interested in “progressing the commercial opportunities” to get into contact with Isis.