Lithium　titanate　battery　suffers　from　high　capacity　fade　for　elevated　temperature　operation.　In　order　to　gain　new　insights　into　the　underlying　degradation　mechanism　of　this　problem,　Li4Ti5O12/LiCoO2　battery　with　8Ah　capacity　was　assembled　and　its　storage　and　cycling　performance　at　60°C　were　investigated.　Electrochemical　impedance　spectroscopy　(EIS)　of　cells　during　cycling　were　measured　with　two-electrode　and　three-electrode　8Ah　pouch　cells.　XRD,　SEM　and　half-cell　characterization　of　the　cycled　cells　were　analyzed.　Accelerating　Rate　Calorimeter　was　used　to　monitor　the　battery　surface　temperature　during　cycling　at　60°　and　3C　rate.　The　results　showed　that　the　capacity　fade　of　this　cell　was　mainly　caused　by　degradation　of　LiCoO2　cathode.　©　2014　IEEE.