Earth Abundant Fe/Mn-Based Layered Oxide Interconnected Nanowires for Advanced K-Ion Full Batteries

Abstract

K-ion battery (KIB) is a new-type energy storage device that possesses potential advantages of low-cost and abundant resource of K precursor materials. However, the main challenge lies on the lack of stable materials to accommodate the intercalation of large-size K-ions. Here we designed and constructed a novel earth abundant Fe/Mn-based layered oxide interconnected nanowires as a cathode in KIBs for the first time, which exhibits both high capacity and good cycling stability. On the basis of advanced in situ X-ray diffraction analysis and electrochemical characterization, we confirm that interconnected KFeMnO nanowires can provide stable framework structure, fast K-ion diffusion channels, and three-dimensional electron transport network during the depotassiation/potassiation processes. As a result, a considerable initial discharge capacity of 178 mAh g is achieved when measured for KIBs. Besides, K-ion full batteries based on interconnected KFeMnO nanowires/soft carbon are assembled, manifesting over 250 cycles with a capacity retention of ∼76%. This work may open up the investigation of high-performance K-ion intercalated earth abundant layered cathodes and will push the development of energy storage systems.

Recent Progress and Perspective in Electrode Materials for K‐Ion Batteries

“…The data were obtained from the literature. [24,57,88,95,99,101,104,107] www.advenergymat.de Adv. Energy Mater.…”

Rechargeable potassium-ion batteries with honeycomb-layered tellurates as high voltage cathodes and fast potassium-ion conductors

“…Amongst them, reversible K-ion insertion at moderate energy density coupled with fast K-ion diffusion rate was observed in layered metal oxides adopting P2-type coordination (prismatic coordination of the K-ions and 2 brucite-like layers in the unit cell). P2-layered oxides with multi-transition metals such as K 2/3 Ni 1/6 Co 1/6 Mn 2/3 O 2 43 and K 2/3 Fe 1/2 Mn 1/2 O 2 44 have further been shown to deliver enhanced electrochemical performance compared to their parent components (i.e., K x M O 2 ( M  = Mn, Co and Fe). This information was very beneficial to us when looking for related layered cathode frameworks with greater potentials.…”

A New Strategy for High‐Voltage Cathodes for K‐Ion Batteries: Stoichiometric KVPO4F

“…[5,[8][9][10][11][12] Layered transition metal oxides (TMOs) have been considered promising candidates for LIB and NIB cathodes because of their dense close-packed structure as well as their high Li and Na diffusivities. [13][14][15] In this respect, K-TMOs, including K x CoO 2 (x= 0.41, 0.6, and 0.67), [16][17] K x MnO 2 (x= 0.3 and 0.5), [18][19] K 0.7 Fe 0.5 Mn 0.5 O 2 , [20] and K 0.67 Ni 0.17 Co 0.17 Mn 0.66 O 2 , [21] have been investigated as cathode materials for KIBs. However, the specific capacities and working voltage of K-TMOs are lower than those of Li-and Na-TMOs due to the strong K + -K + interaction which is much larger than the corresponding Li + -Li + or Na + -Na + interactions.…”

“…However, the specific capacities and working voltage of K-TMOs are lower than those of Li-and Na-TMOs due to the strong K + -K + interaction which is much larger than the corresponding Li + -Li + or Na + -Na + interactions. [16][17][18][19][20][21] The strong K + -K + interaction is due to the large size of K + which increases the distance between the oxygen layers and reduces their effectiveness in screening the K + -K + electrostatic repulsion. This strong interaction results in greater voltage slope and low specific capacity between set voltage limits for layered K-TMOs.…”