%0 Journal Article
%K Cathode
%K Degradation
%K Li-ion battery
%K Raman microscopy
%A Marie Kerlau
%A Marek Marcinek
%A Venkat Srinivasan
%A Robert Kostecki
%B Electrochimica Acta
%D 2007
%F Batt
%G eng
%N 3
%P 1385-1392
%R 10.1016/j.electacta.2007.10.009
%T Reprint of "Studies of local degradation phenomena in composite cathodes for lithium-ion batteries"
%V 53
%8 12/2007
%X <p>LiNi<sub>0.8</sub>Co<sub>0.15</sub>Al<sub>0.05</sub>O<sub>2</sub> and LiNi<sub>1/3</sub>Co<sub>1/3</sub>Mn<sub>1/3</sub>O<sub>2</sub> composite cathodes were cycled in model cells to study interfacial phenomena that could lead to electrode degradation. <em>Ex situ</em> spectroscopic analysis of the tested cathodes, which suffered substantial power and capacity loss, showed that the state of charge (SOC) of oxide particles on the cathode surface was highly non-uniform despite the deep discharge of the Li-ion cell at the end of the test. The inconsistent kinetic behavior of individual oxide particles was attributed to the degradation of electronic pathways within the composite cathodes. A simple theoretical model based on a distributed network showed that an increase of the contact resistance between composite electrode particles may be responsible for non-uniform local kinetic behavior of individual oxide particles and the overall degradation of electrochemical performance of composite electrodes.</p>