
233First-Principles Approach for Cathode Design and Characterisation
estimated from the integrated spin density, as shown in Figure 6.2b and c.
The net spin moments are about +3.79 and +2.85 for Fe and Co in LiMBO
3
(M = Fe and Co), respectively, which correspond to the unpaired electron
spin counts of Fe
2+
(+4) and Co
2+
(+3) at high-spin states. With delithiation,
net moments are observed to decrease to +4.32 and +3.23 for Fe and Co
in MBO
3
(M = Fe and Co), respectively. These values are also close to the
unpaired electron spin counts of Fe
3+
(+5) and Co
3+
(+4) at high-spin states,
indicating that the oxidation states of Fe and Co in Li
x
MBO