V. Focused Fundamental Research - EERE - U.S. Department of ...

Cabana – LBNL
V.E.6 Investigation of Critical Parameters in Li-ion Battery Electrodes (LBNL)
formulation for LiNi 0.5 Mn 1.5 O 4 . This observation implies
that the real composition in the spinel phase is Nidefficient.
Attempts to introduce O vacancies in the
refinements to compensate this deficiency were
unsuccessful. It is concluded that it is compensated by the
partial reduction of Mn 4+ to Mn 3+ , in agreement with XAS
and electrochemical data.
The electrochemical performance of all samples was
evaluated. The best results were obtained for the sample
made at 900C, which shows structural disorder, some
Mn 3+ and large particle size. The worst performance at all
rates was obtained for the sample made at 1000C Figure V -
205). Since this sample contains the largest amount of
rocksalt impurity, it is concluded that this phase is not
active and very detrimental to electrode performance.
Beamline 10.3.2 at the ALS allows the acquisition of
XAS maps of large areas at high spatial resolution (