A formation process to improve the cycling stability of carbon-coated Li2MnSiO4 Lithium-ion cathode materials

• Published in: Solid state ionics Vol. 370; p. 115749
• Main Authors: Phraewphiphat, Thanya, Promwicha, Adisak, Tammawat, Phontip, Limthongkul, Pimpa, Chirawatkul, Prae, Kobsiriphat, Worawarit
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2021; Elsevier BV
• Subjects: Acetic acid; Batteries; Carbon; Cathodes; Charge transfer; Chemical synthesis; Cycles; Electrochemical impedance spectroscopy; Electrode materials; Electrolytes; Electrolytic cells; Lithium; Lithium ions; Sol-gel processes; Spectrum analysis; Structural stability
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/j.ssi.2021.115749

Nitrogen-doped Li2MnSiO4/C (LMS/CN) was synthesized by an acetic acid-assisted sol-gel route. To improve the cycling stability of the LMS/CN cathodes, five formation cycles were employed, by charging cells to 4.5 V and 4.6 V vs. Li+/Li prior to operation cycles, where the cells were charged to a higher potential of 4.8 V. The LMS/CN cells charged to 4.5 V and 4.6 V had 30-cycle capacity retention values of 72.5 and 74.5%, respectively, compared to 60.3% for cells that had not undergone reduced-potential formation cycles. The formation cycles improved the structure and stability of the cathode electrolyte interphase (CEI). Reduced charge transfer and Li+ migration resistance and improved retention of octahedral MnO coordination were shown by ex situ XANES, XPS and electrochemical impedance spectroscopy. •Formation process with low charging potential used to improve cathode cyclability.•Formation process improved the 30th cycle capacity by 19%.•Formation process improved the 30-cycle capacity retention of cells by 23%.•Formation reduced charge transfer resistance, improved interface layer stability.