Paramecium‐Like Iron Oxide Nanotubes as a Cost‐Efficient Catalyst for Nonaqueous Lithium‐Oxygen Batteries

Abstract

Fe2O3‐based catalysts have been developed to achieve a low overpotential and a long cycle life for nonaqueous Li–O2 batteries. However, previous studies focus mainly on nanoparticles or nanoflakes, which have shown limited improvements for battery performance. Here, paramecium‐like Fe2O3 nanotubes (FNTs) are synthesized by a hard‐template method and applied as the catalyst in a nonaqueous Li–O2 battery. The large specific surface area and unique tubular structure of the FNTs allow the nonaqueous Li–O2 battery to deliver a high capacity of 6000 mAh g−1 at a discharge current density of 500 mA g−1 with a low discharge and charge overpotential of approximately 0.19 and 0.85 V, respectively. Moreover, the battery can be operated at a discharge current density as high as 1000 mA g−1 with a capacity of 3940 mAh g−1 and demonstrates an excellent rate capability. The prepared catalyst enables the battery to maintain the discharge capacity and Coulombic efficiency without any degradation for 150 cycles at 500 mA g−1 with a fixed capacity of 500 mAh g−1, which is 110 more cycles than the battery without the catalyst.

Hierarchical NiCo2S4@NiO Core–Shell Heterostructures as Catalytic Cathode for Long‐Life Li‐O2 Batteries

“…The diffraction peaks located at 32.0° and 35.4° can be indexed into (100) and (101) planes of Li 2 O 2 (JCPDS Card No. 74‐0115) and no other phases can be observed, unambiguously indicating the generated Li 2 O 2 as the dominant oxygen reduction products for all the three discharged electrodes . And after deep recharge process, these characteristic peaks related to Li 2 O 2 completely disappear, implying that the discharge/charge capacity contributions are mainly derived from the highly reversible formation and decomposition of Li 2 O 2 .…”

Interfacial Electron Redistribution of Hydrangea‐like NiO@Ni2P Heterogeneous Microspheres with Dual‐Phase Synergy for High‐Performance Lithium–Oxygen Battery

“…The characteristic peaks at 32.0° and 35.4° can be attributed to the (100) and ( 101) crystal planes of Li 2 O 2 , respectively, clearly illustrating that Li 2 O 2 is the main discharge product on the NiO@Ni 2 P electrode. [42,43] After recharging, these diffraction peaks associated with Li 2 O 2 are completely removed, implying that the formation and decomposition of Li 2 O 2 are highly reversible on NiO@Ni 2 P. [44] On the contrary, the LiOH phase is detected on the discharged NiO (Figure S10a, Supporting Information) and Ni 2 P electrodes (Figure S10b, Supporting Information), which may derive from the parasitic reaction on these two electrodes. [45] The formation of LiOH will cause an increase in the charging potential, resulting in a poor rechargeability.…”

Valence Effects of Fe Impurity for Recovered LiNi0.6Co0.2Mn0.2O2 Cathode Materials

“…The X-ray photoelectron spectroscopy (XPS) depth profiling technique, performed via a PHI 5000 VersaProbe II system from Physical Electronics, is carried out to investigate the composition difference of these prepared cathode samples from the surface to the bulk. 32,37,42,44,45 in which first the cathode powder is mixed with the conductive carbon additive (super C65 carbon black) and organic binder polyvinylidene difluoride in the N-methyl-2-pyrrolidone solvent at a weight ratio of 8:1:1 to form a homogeneous slurry after being stirred for several hours. The electrodes are obtained after cast, pressed, and dried.…”

“…In our group, a novel closed-loop recycling process combined with hydrometallurgy and direct recycling methods is successfully developed, which directly resynthesizes the industry-grade NCM cathode materials with comparable performance to commercial ones. Besides, the cost-effective close-loop recycling process exhibits quite broad applicability toward all kinds of commercial cathode materials (NCM, LCO, LMO, LFP, and NCA), demonstrating the great potential of this close-loop method to realize the extensive and sustainable recycle of spent LIBs. ,− For every recycling technology, physical pretreatments are always included to separate each part of spent LIB scraps and obtain the purified leaching liquor for the next chemical process. Although different purification methods have been developed, the impurity components are still detected in leaching solutions, such as Al, Cu, and Fe.…”