Dependence on Dopant Content

The predictions by the Brouwer approximation could be proven experimentally with aluminum and silicon doped LiFeP04. in case of aluminum doped LiFeP04 a further effect was observed besides the changes of the conductivities due to the doping. Here the electronic conductivity flattens at low temperatures, while the decrease of the ionic conductivity becomes steeper at low temperatures (the starting temperatures being the same]. The quantitative analysis succeeds by taking account of defect association  

Calculations of the activation energies of ionic and electronic conduction for both cases, (i] full association and (ii] no association lead to the following  

5 Extraction of Formation Enthalpies, Interaction Enthalpies, and Migration Energies 

In the case of the aluminum doped LiFeP04 sample the association energy between lithium vacancies and the aluminum defects Alpe can be determined to AHy —1 The difference 

6 Comprehensive defect model of the LiFeP04 / FeP04 system 

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