Cycle Life Evaluation of 3 Ah LixMn2O4-based Lithium-Ion Secondary Cells for Low-Earth-Orbit Satellites: II. Harvested Electrode Examination
2008 (English)In: Journal of Power Sources, ISSN 0378-7753, Vol. 185, no 2, 1454-1464 p.Article in journal (Refereed) Published
Lithium-ion batteries area candidate for the energy storage system onboard low-earth-orbit satellites. Terrestrial experiments are able to capture the performance degradation of cells in orbit, therefore providing the opportunity for lifetime investigations. The lifetime performance of 3 Ah commercial LixMn2O4-based pouch cells was evaluated in a matrix of different cycling depths-of-discharge (DODs: 0, 20,40%) and temperatures (25, 45 degrees C). Aged cells were disassembled and the electrochemical performance of harvested electrodes investigated with two- and three-electrode pouch cells. The positive electrode had a larger decrease in capacity than the negative electrode. Both the positive and negative electrode contributed to the increase of cell impedance measured at high states-of-charge (SOCs). The data at low SOCs indicated that the increase of cell impedance was associated with the positive electrode, which showed a significant increase in the magnitude of the high-frequency semi-circle. This SOC-dependence was observed for cells cycled for either extended periods of time or at higher temperatures with a 40% DOD swing. Low-current cycling of positive electrodes revealed a change in the second potential plateau, possibly reflecting a structural change of the LixMn2O4. This could impact on the electrode kinetics and provide a possible explanation for the SOC-dependent change of the impedance.
Place, publisher, year, edition, pages
Amsterdam: ELSEVIER , 2008. Vol. 185, no 2, 1454-1464 p.
Lithium-ion; LEO satellite; Ageing; Porous electrode; Impedance; Three-electrode measurement
IdentifiersURN: urn:nbn:se:kth:diva-8331DOI: 10.1016/j.jpowsour.2008.07.071ISI: 000261748900126ScopusID: 2-s2.0-56249131732OAI: oai:DiVA.org:kth-8331DiVA: diva2:13623
QC 20100618. Uppdaterad från submitted till published (20100709).2008-05-062008-05-062010-07-09Bibliographically approved