Interconnecting 3D Conductive Networks with Nanostructured Iron/Iron Oxide Enables a High-Performance Flexible Battery

Abstract

Aqueous Ni/Fe alkaline batteries with features of low cost and high safety show great potential for application in portable and wearable electronics. However, the poor kinetics of the Fe-based anode greatly limits the large-scale applications of Ni/Fe batteries. Herein, we report an interconnected 3D conductive network with carbon-coated nanostructured iron/iron oxide (3D-Fe/Fe 2 O 3 @C) as an efficient anode for a flexible Ni/Fe battery. A hydrogel precursor is used to molecularly link and confine Fe 3+ to spatial networks, resulting in a uniform dispersion of Fe/Fe 2 O 3 -heterostructured nanoparticles. Theoretical investigations reveal regulated potential loss and improved delocalized carrier density as a result of carbon coating and the mixed metal/metal oxide structure. In addition to these merits, due to the regulated wettability and electroactive surface areas, the 3D-Fe/Fe 2 O 3 @C anode with a high mass loading delivers an extraordinary areal capacity of 3.07 mA h cm −2 , as well as the boosted rate capability and Coulombic efficiency. When coupled with the NiCo 2 O 4 cathode, the flexible quasi-solid-state Ni/Fe battery exhibits an admirable energy density of 15.53 mW h cm −3 and a maximum power density of 761.91 W h cm −3 . The good stability after 20,000 cycles and severe mechanical deformations of the as-fabricated Ni/Fe battery imply it as a promising flexible energy storage device for practical applications.

Understanding the Atomic and Defective Interface Effect on Ruthenium Clusters for the Hydrogen Evolution Reaction

“…The binding energy at ca. 531.8 eV (O 1s XPS spectrum in Figure S15c) also indicates the formation of C–O–Fe species. , Nevertheless, the oxidation state and fine structure of the iron single atom are not well substantiated only based on the single XPS analysis because of the low content of Fe species in CNT–V–Fe (0.15 wt % based on the inductively coupled plasma analysis, Table S1).…”

High–Performance Biscrolled Ni–Fe Yarn Battery with Outer Buffer Layer

“…Even at 7535 mW/cm 3 , the energy density was 229 mWh/cm 3 . Thus, the proposed b–BNF yarn battery outperforms most previously reported Ni–Fe batteries ( Figure 3 d) [ 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 ].…”

“…( c ) Capacity retention and corresponding coulombic efficiency of b–BNF yarn battery. ( d ) Ragone plot of as–fabricated Ni–Fe battery (based on total volume of the cathode and anode) [ 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 ]. ( e ) Photographs showing three b–BNF yarn batteries woven into a commercial textile.…”

Phytic acid assisted ultra-fastin situconstruction of Ni foam-supported amorphous Ni–Fe phytates to enhance catalytic performance for the oxygen evolution reaction

“…3b), the peaks located at 531.4 eV and 532.3 eV belong to the oxygen species in the P–O or –O–H and C–O in phytate ion, respectively. 38–40 Besides, the peaks derived from the oxygen species in metal–O and the physical or chemical adsorption water are also observed at 530.5 eV and 533.1 eV, respectively. 41 The P 2p XPS peak is loaded at 133.5 eV indicating the existence of the P–O bond in Ni–Fe-phy@NF (Fig.…”