Selected future tasks in electrochemical research related to advanced power sources
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FEATURE ARTICLE
Selected future tasks in electrochemical research related to advanced power sources David Malka 1 & Nethanel Shpigel 1 & Ran Attias 1 & Doron Aurbach 1 Received: 31 May 2020 / Revised: 31 May 2020 / Accepted: 31 May 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Preface The purpose of this short paper is to outline important research tasks related to electrochemical power sources. In fact, we can mention four main avenues related to electrochemical science connected to energy challenges, i.e. energy harvesting by photovoltaic cells, hydrogen economy (hydrogen production by electrolysis, followed by its effective storage and use in fuel cells), the energy-water nexus which is related to capacitive interactions (including important topics such as capacitive deionisation and the field of supercapacitors and related devices) and electrochemical energy storage and conversion by batteries.
Major tasks for rechargeable batteries In the field of advanced rechargeable batteries, we can mark four important major uses, i.e. powering portable electronic devices, electro-mobility, very high energy density batteries for unmanned ground transportation (including robots) and aviation (drones), large energy storage for supporting the use of renewable sources like sun and wind. For both portable electronics and electro-mobility, Li-ion batteries are the leading power sources, thanks to their advantages in energy density, reasonable rates and acceptable durability. The challenge is to take this technology further, especially in order to fulfil the high demands of electric vehicles for higher energy density. The limiting factor is the cathode side.
* Doron Aurbach [email protected] 1
Department of Chemistry and BINA–BIU Center for Nanotechnology and Advanced Materials, Bar-Ilan University, 5290002 Ramat-Gan, Israel
Next generation Li-ion batteries for transportation The most important advancement for these systems connects to promising cathode materials relate to two families which has the following general stoichiometry—Li1+xNiyCozMnwO2 (x + y + z + w = 1) [1]. When x = 0 and y➔1 (LNO cathodes), they are termed Ni-rich NCM cathodes. The higher the Ni content, so the specific capacity is higher, up to 240 mAh/g, can be extracted upon charging < 4.3 V vs Li, below the anodic limitation of the electrolyte solutions. However, the higher the Ni content, so these cathodes are unstable. Their stabilisation can be achieved by judicious doping by foreign elements (Al, Zr, W, Ta, Nb) guided by computational work. The use of fluorinated alkyl carbonate co-solvents in the electrolyte solutions can add substantially to stabilisation, thanks to unique surface chemistry that forms passivating surface films. At the anode side, graphite (> 350 mAh/g) can be replaced by carbon-silicon composites, thus doubling the anodes’ specific capacity. It is recommended not to try to extract the full capacity of lithiated silicon, in order to secure durability, as required for EV applications. Combining stabilised LN
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