Page 397 - Polymer-based Nanocomposites for Energy and Environmental Applications

354 Polymer-based Nanocomposites for Energy and Environmental Applications

Fig. 12.10 Schematic representation of NFMO nanofiber and aggregated nanoparticle
structures and their ion-electron conduction behavior.
Adapted with permission from Kalluri S, Hau Seng K, Kong Pang W, Guo Z, Chen Z,
Liu H-K, et al. Electrospun P2-type Na 2/3 (Fe 1/2 Mn 1/2 )O 2 hierarchical nanofibers as cathode
material for sodium-ion batteries. ACS Appl Mater Interfaces 6;2014:8953–8.

interconnection between the nanocrystallites, which enables stable and traced
pathway for ions and electrons during cycling [63]. The difference in ion and electron
transportation in these two structures is given in Fig. 12.10.
Layered transition metal oxide fibers can also be obtained by centrifugal spinning
of PAN solution [64]. These Li-substituted Na layered transition metal oxide 1-D
structured cathodes were produced in several different Li/Na ratios. The electroche-
mical tests showed that the substitution of Na with Li improved the capacity of the
electrode. Furthermore, they exhibited high rate capability and stable cycling over
100 cycles at different charging densities, with 80% capacity retention.

12.3 Discussion and future perspectives

Sodium-ion energy storage technology allows the production of researchable batteries
form abundant and low-cost resources. Since its “rediscovery,” it has attracted a lot of
interest among academicians and industry. Statistical analysis on academic articles
indicates increased interest on Na-ion batteries in the last years. Since 2010, about
1
1100 articles have been published. Among them, almost 900 belong to reports on
2
novel electrode structures and materials. The first prototype of Na-ion 8650 battery
cell was produced by the French research network on electrochemical energy storage
(RS2E) in 2015 [73].
Nanofibers, as 1-D structures with specific properties that enable facile ion diffu-
sion, traced electron transport, and structural integrity during cycling, are attractive

1
Statistical information based on scopus.com search conducted on December 2016 with key words “sodium-
ion” and “battery” within article title.
2
Statistical information based on scopus.com search conducted on December 2016 with key words “sodium-
ion,” “battery,” and “anode” or “cathode” or “electrode” within article title.