TY - JOUR
T1 - New insight into designing a thick-sintered cathode for Li-ion batteries
T2 - the impact of excess lithium in LiCoO2 on its electrode performance
AU - Takeno, Shinichi
AU - Suematsu, Taiki
AU - Kunisaki, Ryusei
AU - Hasegawa, Gen
AU - Watanabe, Ken
AU - Kuwata, Naoaki
AU - Mitsuishi, Kazutaka
AU - Ohnishi, Tsuyoshi
AU - Takada, Kazunori
AU - Suematsu, Kohichi
AU - Shimanoe, Kengo
N1 - Publisher Copyright:
© 2025 The Royal Society of Chemistry.
PY - 2024
Y1 - 2024
N2 - Increasing the capacity of Li-ion batteries is one of the critical issues that must be addressed. A thick and dense electrode using an active material sintered disk is expected to have a high capacity because the volume of the active material is 100% in the cathode. This study focused on LiCoO2, the most well-known active material for the cathode, to improve the properties of the sintered cathode. We investigated the impact of excess Li on various properties. We found that the degree of c-axis orientation in the sintered disk decreased as excess Li increased. In addition, results of 7Li-MAS-NMR suggest the presence of defects resulting from excess Li when the Li excess reached 5.1% or more. The discharge capacity of the LiCoO2 sintered cathode increased as the amount of excess Li increased, and a maximum discharge capacity of 11.2 mA h cm−2 was obtained when the Li excess amount was 7.3%. This result was attributed to the significant improvement in the Li-ion conductivity of LiCoO2 by both the decrease in the degree of c-axis orientation and the introduction of defects due to excess Li. Notably, introducing defects derived from excess Li enhances the Li-ion conductivity. Thus, tuning the amount of excess Li for the LiCoO2 sintered cathode was crucial in enhancing its electrochemical performance as an electrode.
AB - Increasing the capacity of Li-ion batteries is one of the critical issues that must be addressed. A thick and dense electrode using an active material sintered disk is expected to have a high capacity because the volume of the active material is 100% in the cathode. This study focused on LiCoO2, the most well-known active material for the cathode, to improve the properties of the sintered cathode. We investigated the impact of excess Li on various properties. We found that the degree of c-axis orientation in the sintered disk decreased as excess Li increased. In addition, results of 7Li-MAS-NMR suggest the presence of defects resulting from excess Li when the Li excess reached 5.1% or more. The discharge capacity of the LiCoO2 sintered cathode increased as the amount of excess Li increased, and a maximum discharge capacity of 11.2 mA h cm−2 was obtained when the Li excess amount was 7.3%. This result was attributed to the significant improvement in the Li-ion conductivity of LiCoO2 by both the decrease in the degree of c-axis orientation and the introduction of defects due to excess Li. Notably, introducing defects derived from excess Li enhances the Li-ion conductivity. Thus, tuning the amount of excess Li for the LiCoO2 sintered cathode was crucial in enhancing its electrochemical performance as an electrode.
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U2 - 10.1039/d4ta07377k
DO - 10.1039/d4ta07377k
M3 - Article
AN - SCOPUS:85212692407
SN - 2050-7488
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
ER -