A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Effect of Secondary Heat Treatment after a Washing on the Electrochemical Performance of Co-Free LiNi0.975Al0.025O2 Cathodes for Li-Ion Batteries (2024)

Välikangas, J., Laine, P., Hu, T., Tynjälä, P., Selent, M., Molaiyan, P., Jürgen, K., & Lassi, U. (2024). Effect of Secondary Heat Treatment after a Washing on the Electrochemical Performance of Co-Free LiNi0.975Al0.025O2 Cathodes for Li-Ion Batteries. Small, 20(4), Article 2305349. https://doi.org/10.1002/smll.202305349

JYU-tekijät tai -toimittajat

Julkaisun tiedot

Julkaisun kaikki tekijät tai toimittajat: Välikangas, Juho; Laine, Petteri; Hu, Tao; Tynjälä, Pekka; Selent, Marcin; Molaiyan, Palanivel; Jürgen, Kahr; Lassi, Ulla

Lehti tai sarja: Small

ISSN: 1613-6810

eISSN: 1613-6829

Julkaisuvuosi: 2024

Ilmestymispäivä: 15.09.2023

Volyymi: 20

Lehden numero: 4

Artikkelinumero: 2305349

Kustantaja: Wiley-VCH Verlag

Julkaisumaa: Saksa

Julkaisun kieli: englanti

DOI: https://doi.org/10.1002/smll.202305349

Julkaisun avoin saatavuus: Avoimesti saatavilla

Julkaisukanavan avoin saatavuus: Osittain avoin julkaisukanava

Julkaisu on rinnakkaistallennettu (JYX): https://jyx.jyu.fi/handle/123456789/89154

Tiivistelmä

The steadily growing electric vehicle market is a driving force in low-cost, high-energy-density lithium-ion battery development. To meet this demand, LiNi0.975Al0.025O2 (LNA), a high-energy-density and cobalt-free cathode material, has been developed using a low-cost and efficient co-precipitation and lithiation process. This article explores how further processing (i.e., washing residual lithium from the secondary particle surface and applying a secondary heat treatment at 650 °C) changes the chemical environment of the surface and the electrochemical performance of the LNA cathode material. After washing, a nonconductive nickel oxide (NiO) phase is formed on the surface, decreasing the initial capacity in electrochemical tests, and suppressing high-voltage (H2) to (H3) phase transition results in enhanced cycle properties. Furthermore, the secondary heat treatment re-lithiates surface NiO back to LNAand increases the initial capacity with enhanced cycle properties. Electrochemical tests are performed with the cells without tap charge to suppress the H2 to H3 phase transition. Results reveal that avoiding charging cells at a high voltage for a long time dramatically improves LNA's cycle life. In addition, the gas analysis tests performed during charge and discharge to reveal how the amount of residual lithium compounds on the surface affects gas formation are studied.

YSO-asiasanat: litiumioniakut; elektrodit; lämpökäsittely; pintakemia; sähkökemia

Liittyvät organisaatiot

OKM-raportointi: Kyllä

VIRTA-lähetysvuosi: 2023

Alustava JUFO-taso: 3