A Low‐Strain Potassium‐Rich Prussian Blue Analogue Cathode for High Power Potassium‐Ion Batteries

Abstract

Most of the cathode materials for potassium ion batteries (PIBs) suffer from poor structural stability due to the large ionic radius of K + ,r esulting in poor cycling stability.Here we report al ow-strain potassium-richK 1.84 Ni[Fe-(CN) 6 ] 0.88 •0.49 H 2 O(KNiHCF) as acathode material for PIBs. The as-prepared KNiHCF cathode can deliver reversible discharge capacity of 62.8 mAh g À1 at 100 mA g À1 ,w ith ah igh discharge voltage of 3.82 V. It can also achieve asuperior rate performance of 45.8 mAh g À1 at 5000 mA g À1 ,w ith ac apacity retention of 88.6 %after 100 cycles.The superior performance of KNiHCF cathode results from low-strain de-/intercalation mechanism, intrinsic semiconductor property and low potassium diffusion energy barrier.T he high power density and long-term stability of KNiHCF//graphite full cell confirmed the feasibility of K-rich KNiHCF cathode in PIBs.T his work provides guidance to develop Prussian blue analogues as cathode materials for PIBs.

Extraordinarily stable and wide‐temperature range sodium/potassium‐ion batteries based on 1D SnSe2‐SePAN composite nanofibers

“…At the full charge state, the affinity of the Se‐side of the SePAN fiber to adsorb SnSe 2 (Figures 5A and S15A, E ads = −2.91 eV) and Na (Figures 5B and S15B, E ads = −3.53 eV) are higher than that of N‐doped graphene sheet (Figure S16A, E ads = −0.44 eV and Figure S16B, E ads = −0.58 eV), as shown in Figure 5E,F. The above result shows that SePAN fiber is favorable to inhibiting SnSe 2 particle coalescence and concentrating the Na + ions on the surface, thus strengthening reaction kinetics 80,81 . Afterwards, at the full discharge state, one Na 2 Se molecule and Sn atom were applied to stand for discharge products.…”

“…The above result shows that SePAN fiber is favorable to inhibiting SnSe 2 particle coalescence and concentrating the Na + ions on the surface, thus strengthening reaction kinetics. 80,81 Afterwards, at the full discharge state, one Na 2 Se molecule and Sn atom were applied to stand for discharge products. From Figure 5G,H, the affinity of the N-side on PAN to adsorb Na 2 Se (Figures 5C and S15C, E ads = À4.14 eV) and Sn (Figures 5D and S15D, E ads = À5.26 eV) are stronger than that of N-doped graphene sheet (Figure S16C,D, E ads = À0.76 eV for Na 2 Se and E ads = À0.95 eV for Sn), illustrating PAN is expected to remit discharge products coalescence and promote their uniform distribution, thus enhancing the reversibility of electrode.…”

Progress and challenges of Prussian blue analogs for potassium-ion batteries: a perspective on redox-active transition metals

“…Li's group 82 reported a simple co-precipitation method to synthesize the Ni-PBA electrode material K 1.84 Ni[Fe(CN) 6 ] 0.88 ·0.49H 2 O. This material was composed of homogeneous nanoparticles with a size in the range of 10–20 nm (Fig.…”

Oriented Assembled Prussian Blue Analogue Framework for Confined Catalytic Decomposition of Ammonium Perchlorate

“…[15][16][17][18] With the development of material science, PBA also shows a higher level of structural adjustability, and special structures such as nanoparticles and nano sheets have shown good catalytic effect. [19][20][21] However, during the thermal decomposition of AP, partial deactivation of catalytic sites caused by catalyst agglomeration will undoubtedly cause its ability to explore catalysts. [22][23][24][25][26][27] Based on these difficulties, 3-dimensional frame structure is considered to be an effective solution.…”