@article { , title = {Insight into lithium transport in lithium nitridometallate battery materials from muon spin relaxation}, abstract = {Muon spin relaxation and powder neutron diffraction have been combined to study three lithium cobalt nitride battery materials. Neutron diffraction shows that these retain the P6/mmm space group of Li3N with Co located only on Li(1) sites. The lattice parameters vary smoothly with the degree of metal substitution, such that the [Li2N] layers expand while the layer separation contracts, as observed previously for similar series of Cu- and Ni-substituted materials. However, in contrast to the latter, the Li3-x-yCoxN phases exhibit Curie-Weiss paramagnetism and this prevents the use of nuclear magnetic resonance to measure Li+ transport parameters. Therefore, muon spin relaxation has been employed here as an alternative technique to obtain quantitative information about Li+ diffusion. Muon spin relaxation shows that Li+ diffusion in Li3-x- yCoxN is anisotropic with transport confined to the [Li2N] plane at low temperature and exchange between Li(1) and Li(2) sites dominant at high temperature. By a comparison with previous studies some general trends have been established across a range of Cu-, Ni- and Co-substituted materials. For intra-layer diffusion Ea decreases as metal substitution increases and the corresponding expansion of the layers results in a more open pathway for Li+ diffusion. However, an optimal value of x is found with a ≈ 3.69 Å after which the concomitant contraction in layer spacing reduces the polarizability of the lattice framework.}, doi = {10.1039/c2cp43318d}, eissn = {1463-9076}, issn = {1463-9076}, issue = {3}, journal = {Physical Chemistry Chemical Physics}, publicationstatus = {Published}, publisher = {Royal Society of Chemistry}, url = {https://nottingham-repository.worktribe.com/output/1005401}, volume = {15}, year = {2013}, author = {Powell, Andrew S. and Stoeva, Zlatka and Lord, James S. and Smith, Ronald I. and Gregory, Duncan H. and Titman, Jeremy J.} }