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A cost-effective perovskite fluoride KCuF3 material has been introduced as an advanced anode for lithium-ion capacitors (LICs) and lithium-dual-ion batteries (Li-DIBs), showing a conversion mechanism and pseudocapacitive kinetics for Li ion storage. [ABSTRACT FROM AUTHOR]

Lithium-ion capacitors (LICs) and lithium-ion batteries (LIBs) have drawn particular interest as renewable and green energy storage devices. However, the behavior of LICs and LIBs is largely limited by the sluggish kinetics and inferior cycling stability of conventional insertion and alloying-type anodes. In this work, we demonstrate novel pseudocapacitive conversion-type and robust hetero-nanostructural cobalt–manganese perovskite fluorides/reduced graphene oxides (KCMF(3 : 2)/rGO) anodes with superior kinetics and stability for advanced LICs, LIBs and their hybrids (LIC/Bs). The KCMF(3 : 2)/rGO candidate composed of stoichiometric KCo0.54Mn0.46F3 and approximately 11 wt% rGO exhibits superior performance to the solvothermally synthesized pure KCMF(3 : 2) and U-KCMF(3 : 2)/rGO composites without ball-milling treatment, which largely benefits from the conversion pseudocapacitance characteristics and strong synergistic effect of the robust perovskite fluorides/graphene hetero-nanostructures. A typical pseudocapacitive conversion reaction mechanism for the perovskite KCMF(3 : 2) anode can be deduced by various ex situ characterizations and electrochemical techniques. The designed LIBs, LICs and LIC/Bs with the KCMF(3 : 2)/rGO as the anode and activated carbon (AC), LiFePO4 (LFP) and AC/LFP(1 : 3) as cathodes respectively show remarkable performance in a broad temperature range. This work provides new insight of pseudocapacitive conversion-type and robust hetero-nanostructural electrode materials for advanced lithium-ion energy storage and will have a significant impact on the development of high-performance energy storage devices. [ABSTRACT FROM AUTHOR]

A vacancy defective perovskite Na0.85Ni0.45Co0.55F3.56 nanocrystal (NNCF) has been introduced as an advanced anode for Li-ion capacitors (LICs), Li-ion batteries (LIBs) and Li-dual-ion batteries (Li-DIBs), exhibiting the surface conversion and insertion hybrid mechanisms for Li-ion storage. [ABSTRACT FROM AUTHOR]

Perovskites K–Ni–Co–F (denoted as KNCF) with various Ni/Co ratios have been introduced as high-performance anodes for nonaqueous Li-ion capacitors (LICs) and dual-ion batteries (DIBs). The optimal KNCF (Ni/Co = 1-6) material possesses the stoichiometric formula of KNi0.1Co0.9F3 with cubic nanocrystal morphology and hierarchical porous structure. The KNCF (1-6) electrode shows a typical surface conversion reaction mechanism with a synergistic contribution of Ni and Co electroactive species for Li-ion storage. The KNCF (1-6)//activated carbon (AC) LIC with the anode precharged (or prelithiated) exhibits much higher energy/power densities and cycling stability than the non-precharged one, moreover, the overall performance is better than those of the KNCF (1-0)//AC and KNCF (0-1)//AC LICs. Interestingly, the constructed KNCF (1-6)//AC + LiFePO4 (LFP) (1 : 1) LIC exhibits better performance than the KNCF (1-6)//AC LIC by using a capacitor–battery hybrid cathode with higher specific capacity, and the performance of the KNCF (1-6)//AC LIC is also enhanced by the precharging treatment of both the KNCF (1-6) anode and AC cathode. The designed KNCF (1-6)//graphite (918) DIB exhibits better performance than the other three DIBs with the 918 + AC (1 : 1), 918 + LFP (1 : 1) and 918 + AC + LFP (1 : 1 : 1) cathodes. Furthermore, the designed LICs and DIBs also show a remarkable behavior at low (−20 °C) and high (40 °C) temperatures. [ABSTRACT FROM AUTHOR]

Perovskite KNi0.8Co0.2F3 nanocrystals were introduced as potential electrode materials for supercapacitors, which exhibited superior specific capacity and rate behavior owing to the optimal synergistic effect of Ni and Co redox species. The AC//KNi0.8Co0.2F3 asymmetric capacitor delivered high power and energy densities together with excellent cycling stability. [ABSTRACT FROM AUTHOR]

A cost-effective perovskite fluoride KCuF 3 material has been introduced as an advanced anode for lithium-ion capacitors (LICs) and lithium-dual-ion batteries (Li-DIBs), showing a conversion mechanism and pseudocapacitive kinetics for Li ion storage.

A vacancy defective perovskite Na0.85Ni0.45Co0.55F3.56 nanocrystal (NNCF) has been introduced as an advanced anode for Li-ion capacitors (LICs), Li-ion batteries (LIBs) and Li-dual-ion batteries (Li-DIBs), exhibiting the surface conversion and insertion hybrid mechanisms for Li-ion storage.