Amorphous iron phosphate (FePO4) has attracted enormous attention as a promising cathode material for sodium‐ion batteries (SIBs) because of its high theoretical specific capacity and superior electrochemical reversibility. Nevertheless, the low rate performance and rapid capacity decline seriously hamper its implementation in SIBs. Herein, we demonstrate a sagacious multi‐step templating approach to skillfully craft amorphous FePO4 yolk–shell nanospheres with mesoporous nanoyolks supported inside the robust porous outer nanoshells. Their unique architecture and large surface area enable these amorphous FePO4 yolk–shell nanospheres to manifest remarkable sodium storage properties with high reversible capacity, outstanding rate performance, and ultralong cycle life.

In recent years, hybrid perovskite solar cells (PSCs) have attracted much attention owing to their low cost, easy fabrication, and high photoelectric conversion efficiency. Nevertheless, solution‐processed perovskite films usually show substantial structural disorders, resulting in ion defects on the surface of lattice and grain boundaries. Herein, a series of D–π–A porphyrins coded as CS0, CS1, and CS2 that can effectively passivate the perovskite surface, increase VOC and FF, reduce the hysteresis effect, enhance power conversion efficiency to be higher than 22%, and improve the device stability is developed. The results in this study demonstrated that the donor–π–acceptor type porphyrin derivatives are promising passivators that can improve the cell performance of PSCs.

No abstract

Most potassium-ion battery (PIB) cathode materials have deficient structural stability because of the huge radius of potassium ion, leading to inferior cycling performance.W e report the controllable synthesis of an ovel low-strain phosphate material K 3 (VO)(HV 2 O 3 )(PO 4 ) 2 (HPO 4 )(denoted KVP) nanorulers as an efficient cathode for PIBs.The as-synthesized KVP nanoruler cathode exhibits an initial reversible capacity of 80.6 mAh g À1 under 20 mA g À1 ,with alarge average working potential of 4.11 V. It also manifests an excellent rate property of 54.4 mAh g À1 under 5Ag À1 ,w ith ah igh capacity preservation of 92.1 %o ver2 500 cycles.T he outstanding potassium storage capability of KVP nanoruler cathode originates from al ow-strain K + uptake/removal mechanism, inherent semiconductor characteristic,a nd small K + migration energy barrier.The high energy density and prolonged cyclic stability of KVP nanorulers//polyaniline-intercalated layered titanate full battery verifies the superiority of KVP nanoruler cathode in PIBs.