Multicomponent two-layered cathode for thick sintered lithium-ion batteries

Abstract

Material and electrochemical properties for three multicomponent thick sintered electrode configurations were evaluated. Relative location of the lower electronic conductivity LiMn2O4 phase dramatically influenced electrochemical material outcomes.

Enhancing low electronic conductivity materials in all active material electrodes through multicomponent architecture

“…, the (003) peak at a 2 θ of 18.96°) as expected. Although the thermal treatment would be expected to result in some interdiffusion between Co and Mn/Ni, 30,42,43 from XRD the LCO and LNMO materials appeared to remain segregated and compositionally and structurally distinct. More specifically, the (003) peak for pure LNMO was distinctly located at 2 θ of 18.63°, while for LCO the corresponding peak was at 2 θ of 18.96°.…”

“…Such low reversibility was likely from the negative impact from ball-milling, consistent with previous observations for these same materials. 30 The AAM treatment composite LCO achieved 169 mA h g −1 LCO for the first charge cycle and 146 mA h g −1 LCO for the first discharge cycle. Such improvement in discharge capacity and reversibility was possibly due to the enhanced LCO crystallinity from heat treatment, also consistent with a prior report.…”

“…A large amount of Li intercalated into the LCO, but this capacity was concentrated in the current collector region. Such observation was consistent with previous thick AAM electrode reports, 11,12,30 where an electrode with a flat OCV curve and relatively higher electronic conductivity (relative to ionic conductivity) resulted in a reaction front which initiated from the separator and propagated towards the current collector. Correspondingly, the ionic overpotential rose and fell depending on whether it was further from or closer to the separator, respectively.…”

“…22,23 Alternative layered oxide cathode materials with higher capacity often substitute Co with lower cost Ni and Mn, however, electronic conductivities of these materials are intrinsically much lower than LCO. 24–30…”

“…LNMO was chosen as an exemplar material because it is Co-free, has relatively low electronic conductivity to make the impact of the blending with LCO more pronounced, 31,32 and has the same Li stoichiometry and layered structure as LCO and thus deleterious interface formation during thermal processing was expected to be less likely. 19,30,33…”