Negative thermal expansion (NTE), the phenomenon of a material contracting upon heating, is a relatively unique occurrence with practical applications and fundamental structure implications. The complex metal oxides in this work exhibit contraction upon incorporation of lithium, which enables high-rate performance and good cycle life in lithium-ion battery applications. That discovery led us to investigate their thermal expansion properties and initial measurements confirm that these materials also exhibit NTE. We propose to perform a detailed high-resolution in situ neutron diffraction study of thermal expansion in these complex metal oxide structures as a function of structure and composition.