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Size reduction in nanocrystals leads to a variety of unexpected exciting phenomena due to enhanced surface-to-volume
ratio and reduced length for the transport [1, 2]. Here, we consider the effects of nano-size on the kinetics and
thermodynamics and study its bearing on the lithium storage performance in insertion and conversion based Li storage
mechanism.
Firstly, we investigate the storage performance of nanocrystalline LiMnPO4 by insertion reaction. Ball milling
of LiMnPO4 synthesized by soft-template method with carbonaceous materials helps to reduce the grain size as well as
formation of a thin layer of carbon coating. Nanostructuring by ball milling process promotes high surface area of the
active electrode material for improved electrolyte wetting, short transport length for Li diffusion while the carbon
coatings facilitates electronic wiring all of which contribute to the enhanced storage performance. Additionally, we
show that combining nanostructuring with divalent cation doping further improves the storage performance of the
system which make them potential high voltage cathodes for real applications.
Secondly, we discuss the size effect on thermodynamics during the conversion reaction, considering Fe2O3 as
an example. The process of Li storage by conversion induces drastic size reduction, leading to stabilization of
metastable phase of γ-Fe2O3. We show here that apart from kinetics, thermodynamics at nanosize also limit the rate of
conversion reaction. Finally, we show that Fe2O3 can be a potential anode material for practical applications as they
demonstrate a high degree of reversibility ~ 90% and excellent high rate performance.
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