1 research outputs found
Exploring the nanoscale origin of performance enhancement in LiNiMnO batteries due to chemical doping
Despite significant potential as energy storage materials for electric
vehicles due to their combination of high energy density per unit cost and
reduced environmental and ethical concerns, Co-free lithium ion batteries based
off layered Mn oxides presently lack the longevity and stability of their
Co-containing counterparts. Here, we demonstrate a reduction in this
performance gap via chemical doping, with LiNiMnO
achieving an initial discharge capacity of 159 mAhg at C/3 rate and a
corresponding capacity retention of 94.3% after 150 cycles. We subsequently
explore the nanoscale origins of this improvement through a combination of
advanced diffraction, spectroscopy, and electron microscopy techniques, finding
that optimized doping profiles lead to an improved structural and chemical
compatibility between the two constituent sub-phases that characterize the
layered Mn oxide system, resulting in the formation of unobstructed lithium ion
pathways between them. We also directly observe a structural stabilization
effect of the host compound near the surface using aberration corrected
scanning transmission electron microscopy and integrated differential phase
contrast imaging.Comment: 20 pages, 8 figure