30.September 2025

Vanu liitium-ioonakusid ümber töödeldes tekib praegu hulganisti grafiiti, millega pole enam midagi teha. Nüüd õnnestus Eesti keemilise füüsika nooremteaduril valmistada oma doktoritöös sellest toorainet uut tüüpi akudele.

When recycling old lithium-ion batteries, a large amount of graphite is currently produced with no further use. Now, an Estonian junior researcher in chemical physics has succeeded in using this material as raw material for new types of batteries in his doctoral thesis.

Liitium-ioonakusid on igal pool. Neid kasutatakse telefonides, arvutites, tööriistades ja elektriautodes. Samuti suurtes energiasalvestuslahendustes, näiteks akupankades.

Reio Praats, nooremteadur Keemilise ja Bioloogilise Füüsika Instituudist, ütleb, et akude koobaltit ja niklit saab taaskasutada. Aga jääb tavaliselt jäätmeks. Grafiit on oluline aku töös ja moodustab sageli kuni veerand aku kaalust.

Praegu toodetakse enamik i Hiinas. See tekitab Euroopas probleeme. Reio Praats leidis s viisi, kuidas kasutada vanadest akudest saadud i uute akude jaoks.

Tema töös kasutati e jääke, mis sisaldavad peamiselt i ja vähesel määral metalle. Praats valmistas sellest elektrokatalüsaatoreid, mis on vajalikud uut tüüpi akude valmistamiseks.

Metall-õhk akud on odavamad ja kui . Elektrokatalüsaatorid aitavad neil akudel paremini töötada. Praats ütleb, et tema tulemused olid ootamatud, kuid edukad.

Varajasemalt peeti vanadest akudest saadud i jäätmeks. Praats arvab, et selliseid materjale tuleks taas kasutada, et vähendada jäätmeid ja säästa ressursse.

Vanad töödeldakse püro- ja hüdrometallurgiliste meetoditega. Püroprotsessis põletatakse ära. Hüdroprotsessis purustatakse akud ja eraldatakse . Järele jääb , mis sisaldab i ja metallijääke.

Praatsi eesmärk oli leida viis, kuidas kasutada musta massi jääki elektrokatalüsaatorite valmistamiseks. Need katalüsaatorid kiirendavad keemilisi reaktsioone, mis on olulised uut tüüpi akude jaoks.

Praegu kasutatakse elektrokatalüsaatorite valmistamiseks haruldasi ja kalleid metalle, nagu plaatina ja iriidium. Praats leidis odavama ja keskkonnasõbralikuma alternatiivi.

Tema töös kasutati jääki, mis sisaldab i ja metallijääke. Need metallid olid tähtsad elektrokatalüsaatorite valmistamisel. Praatsi katsed näitasid, et tema materjalid on võrreldes väärismetallidega paremad.

Praegu on sadu tuhandeid tonne musta massi jääki, mida ei osata kasutada. Praatsi töö aitab leida neile uue kasutuse ja arendada t. See aitab ka paremini salvestada rohelist energiat, nagu päikese- ja tuuleenergiat.

Reio Praats kaitseb oma d 29. septembril Tallinna Tehnikaülikoolis. Tema töö keskmes on e jäätmete uuesti kasutamine uute akude jaoks.

Lithium-ion batteries are everywhere. They are used in phones, computers, tools, and electric cars. Also in large energy storage solutions, such as power banks.

Reio Praats, a junior researcher at the Institute of Chemical and Biological Physics, says that cobalt and nickel from batteries can be recycled. But graphite usually ends up as waste. Graphite is crucial for battery operation and often makes up to a quarter of the battery's weight.

Currently, most graphite is produced in China. This creates supply security issues in Europe. Reio Praats found a way in his doctoral thesis to use graphite from old batteries for new batteries.

His work used lithium-ion battery waste, which mainly contains graphite and small amounts of metals. Praats produced electrocatalysts from this, which are needed for manufacturing new types of batteries.

Metal-air batteries are cheaper and more environmentally friendly than lithium-ion batteries. Electrocatalysts help these batteries perform better. Praats says his results were unexpected but successful.

Previously, graphite from old batteries was considered waste. Praats believes such materials should be reused to reduce waste and save resources.

Old lithium-ion batteries are processed using pyro- and hydrometallurgical methods. In the pyro process, graphite is burned away. In the hydro process, batteries are crushed, and valuable metals are extracted. What remains is a black mass containing graphite and metal residues.

The goal of Praats' doctoral thesis was to find a way to use the black mass residue for producing electrocatalysts. These catalysts accelerate chemical reactions essential for new types of batteries.

Currently, rare and expensive metals like platinum and iridium are used to make electrocatalysts. Praats found a cheaper and more environmentally friendly alternative.

His work used residue containing graphite and metal traces. These metals were important in making the electrocatalysts. Praats' experiments showed that his materials performed better compared to precious metals.

Currently, there are hundreds of thousands of tons of black mass residue that cannot be utilized. Praats' work helps find new uses for them and develop a circular economy. It also aids in better storage of green energy, such as solar and wind power.

Reio Praats will defend his doctoral thesis on September 29 at Tallinn University of Technology. His work focuses on reusing lithium-ion battery waste for new batteries.