Theoretical Discharge Capacity Research Articles

Promoting polysulfides conversion by hexagonal-like V-MOF-derived VC-doped carbon nanotubes for lithium-sulfur batteries

Lithium-sulfur batteries (LSBs) are one of the representatives of a new generation of high-performance batteries, due to their large theoretical specific discharge capacity, high energy density and low cost et al. However, shuttle effect and slow conversion kinetics of polysulfides (LiPSs) hinder the performance of LSBs. In order to mitigate shuttle effect, metal-organic frameworks are introduced. Carbon nanotubes (CNTs) is used as composite cathode, due to their high electrical conductivity. V-MOF/CNTs-derived hexagonal VC/CNTs nanosheets are successfully synthesized and used as the sulfur host. VC/CNTs nanosheet with mesoporous structure can provide a lot of active sites. VC nanosheets are uniformly distributed and interconnected with CNTs to form a conductive network structure. VC/CNTs has excellent chemical adsorption and catalytic properties on polysulfides, which can improve the redox reaction kinetics and the adsorption capability. Due to the synergistic effects, S/VC/CNTs has an excellent cycling stability. S/VC/CNTs shows a significant initial specific capacity of 1370 mAh g−1 at 0.1 C. Capacity decay rate per cycle is about 0.037 % After 500 cycles at 0.5 C, the Coulomb efficiency is nearly to 100 %. The results show that the introduction of VC/CNTs composites with special hexagonal structure can accelerate the catalytic electrochemical reaction, and the dissolution and diffusion of polysulfides are well controlled.

Boosting the Electrochemical Performance of Primary and Secondary Lithium Batteries with Mn-Doped All-Fluoride Cathodes.

Transition metal fluorides are potentially high specific energy cathode materials of next-generation lithium batteries, and strategies to address their low conductivity typically involve a large amount of carbon coating, which reduces the specific energy of the electrode. In this study, MnyFe1-yF3@CFx was generated by the all-fluoride strategy, converting most of the carbon in MnyFe1-yF3@C into electrochemical active CFx through a controllable NF3 gas phase fluorination method, while still retaining a tightly bound graphite layer to provide initial conductivity, which greatly improved the energy density of the composite. This synergistic effect of nonfluorinated residual carbon (∼11%) and Mn doping ensures the electrochemical kinetics of the composite. The loading mass of the active substance had been increased to 86%. The theoretical and actual discharge capacity of MnyFe1-yF3@CFx composite was up to 765 mAh g-1 (pure FeF3 is 712 mAh g-1) and 728 mAh g-1, respectively. The discharge capacity at the high-voltage (3.0 V) platform was more than three times higher than that of the non-Mn-doped composite (FeF3@CFx).

First Principles Calculations of Novel Binary Transition Metal Oxides NaCr0.5X0.5O2 (X = Y, Tc, Rh) for Na-Ion Batteries

Recently, layered transition metal oxides have demonstrated voltage windows favorable for use as cathodes in sodium-ion batteries, leading to increased specific capacity and energy density. Here, NaCr0.5Y0.5O2, NaCr0.5Tc0.5O2, and NaCr0.5Rh0.5O2 were studied by using first-principles calculations to elucidate their properties. There is a trigonal arrangement in the structure of both pure and substituted NaCrO2. Structural characteristics reveal the ferromagnetic behavior of these compounds (NaCr0.5X0.5O2; X = Y, Tc, Rh). We calculated the density of states and spin-polarized electronic band structures for the three compounds tested. NaCr0.5Y0.5O2 and NaCr0.5Rh0.5O2 exhibit diluted magnetic semiconductor (DMS) behavior, while NaCr0.5Tc0.5O2 has half-metallic (HM) behavior. The substitutional material’s ferromagnetic nature is confirmed by the negative values of the exchange constants (Nօ α and Nօ β). The fractional value of the magnetic moment also confirms the DMS nature of NaCr0.5Y0.5O2 and NaCr0.5Rh0.5O2, while the HM behavior is confirmed by the integral value of the magnetic moment for NaCr0.5Tc0.5O2. The thermoelectric characteristics were computed using the BoltzTraP code. Alectrochemical analysis of NaCr0.5Y0.5O2 showed a theoretical discharge capacity of 400 mhAg−1 and an average intercalation voltage of 4.87 V, calculated from the total energies of the optimized compounds and their de-sodianted phases. These theoretical computations demonstrate that the binary layered TM oxides studied are appropriate substances to employ in coin cell fabrication as cathodes.

Investigation of Zinc and Chromium Substitution Nickel-rich LiNi1−x−yZnyCrxO2 Cathode Materials to Improve the Redox Reaction of Lithium-ion Battery: A First-principles Study

First-principles calculations are employed to investigate the structural, electronic, magnetic, thermoelectric, and electrochemical characteristics of Nickel-rich layered cathodes by substitution of Zn and Cr such as LiNi1−x−yZnyCrxO2 (with x = 0.00, 0.16 and 0.32, y = 0.00 and 0.16). The structure of pure LiNiO2 and substituted are organized in a trigonal arrangement inside the P3m1 space group. Using PBE-GGA approximation, the spin-polarized calculation of pure LiNiO2 in a spin-down channel exhibits a band gap of 0.48 eV. Whereas, Zn and Cr substitution results in the band gap reduction to zero, and metallic behavior is observed. Electronic charge density calculation Ni(Zn, Cr)-O reveals covalent bonding. In electrochemical investigation, by the increasing substitution concentration of Zn and Cr in LiNi1−x−yZnyCrxO2 significant improvements are observed at 4.65–3.89 V potential with a good theoretical discharge capacity of 48–246 mAhg−1. The exchange constants N∘α and N∘β demonstrate negative values that validate the ferromagnetic nature of substituted material. The thermoelectric parameters have been determined using the BoltzTraP code and the highest ZT value of 0.35 is obtained for LiNi0.52Zn0.16Cr0.32O2. These results offer a new perspective on the potential of doping techniques for Nickel-rich cathode materials, providing helpful insight for the development of high-performance cathodes for Lithium-ion battery applications.

Na3V2(PO4)3-decorated Na3V2(PO4)2F3 as a high-rate and cycle-stable cathode material for sodium ion batteries.

Since Na3V2(PO4)3 (NVP) possesses modest volume deformation and three-dimensional ion diffusion channels, it is a potential sodium-ion battery cathode material that has been extensively researched. Nonetheless, NVP still endures the consequences of poor electronic conductivity and low voltage platforms, which need to be further improved. On this basis, a high voltage platform Na3V2(PO4)2F3 was introduced to form a composite with NVP to increase the energy density. In this study, the sol-gel technique was successfully used to synthesize a Na3V2(PO4)2.75F0.75/C (NVPF·3NVP/C) composite cathode material. The citric acid-derived carbon layer was utilized to construct three-dimensional conducting networks to effectively promote ion and electron diffusion. Furthermore, the composites' synergistic effect accelerates the quick ionic migration and improves the kinetic reaction. In particular, NVP as the dominant phase enhanced the structural stability and significantly increased the capacitive contribution. Therefore, at 0.1C, the discharge capacity of the modified NVPF·3NVP/C composite is 120.7 mA h g-1, which is greater than the theoretical discharge capacity of pure NVP (118 mA h g-1). It discharged 110.9 mA h g-1 of reversible capacity even at an elevated multiplicity of 10C, and after 200 cycles, it retained 64.1% of its capacity. Thus, the effort produced an optimized NVPF·3NVP/C composite cathode material that may be used in the sodium ion cathode.

Bi2O3 Intercalated SWCNT/Sulphur (S) Composite Electrodes for Stable & High Performance Li-S Batteries

In the present work, bismuth oxide (Bi2O3) nanoparticles have been coupled chemically with SWCNT/sulphur (S) composites. Here an architecture constructed by rooting bismuth oxide into SWCNT/sulphur composites could enhance the electrochemical performance of the system. X-ray diffraction (XRD), Raman & Scanning electron microscopy (SEM) measurements of prepared composites were executed to study structural and morphological properties. High theoretical discharge capacity (690 mAh/g) and rate capability expected due to favourable surface structures of SWCNT/S composites which may cause fast redox reaction and high immobilization ability towards intermediate polysulphides. The detailed results of the study will be discussed during the presentation of meeting. Keywords: Bi2O3, SWCNT-S composites, Structural & surface morphology, Electrochemical performance

Interfacial mechanochemical reaction synthesizes alkynyl porous carbon to firm cyclic lithium-sulfur batteries

Due to the high theoretical discharge capacity and energy density, lithium-sulfur batteries have received lots of interest. However, the low sulfur utilization rate and quick capacity reduction are arisen out of the weak electrical conductivity of sulfur and the shuttle effect of polysulfides. Alkynyl-based porous carbon are prepared by interfacial mechanochemical reaction with CaC2 and C6Br6 as raw materials. The influence of the ratio of raw materials on the pore-structure of alkynyl-based porous carbon is investigated. The obtained APC-51 with a specific surface area (462.745 m2 g−1) has graded porosity structure and a relatively high carbon content (63.30 wt%). The initial discharge specific capacity of the lithium-sulfur battery assembled by APC-51/S as the positive electrode is 1017.0 mAh g−1 at 0.1 C and remains 720.6 mAh g−1 after 100 cycles. The prepared alkynyl-based porous carbon allows both physically and chemically adsorb on polysulfides assigned to its graded porosity structure and alkynyl functional groups.

Electrolyte Solvation Structure Regulation Promotes Aluminum–Air Batteries to Approach Theoretical Discharge Capacity

Aluminum–air batteries (AABs) feature high energy density and no limitations for charging facilities but suffer from severe self-corrosion reactions. Suppressing the side reaction between water and aluminum is the fundamental strategy to boost AAB performance. Herein, we first disclose that addition of sodium formate (HCOONa) can largely remold the solvation structure of the classic NaOH electrolyte and greatly reduce the amount of free water, thus constructing AABs close to their theoretical capacity. Ab initio molecular dynamics simulations show that multiple Na+ and H2O form hydrated Na+ ion clusters [Nam(OH2)7m]m+ in the HCOONa–NaOH electrolyte. Meanwhile, HCOO– enters the first solvation layer of Na+ and forms a “stable triangle” with Na+ and H2O. The coordination network formed by Na+, H2O, and HCOO– results in a very low level of free water. Moreover, HCOO– further forms a self-assembled passivation layer on the Al surface. As such, the self-corrosion rate of Al in the HCOONa-based electrolyte is drastically reduced. More encouragingly, the ultrahigh capacity (2767 mAh g–1) delivered by AABs using the hybrid electrolyte reaches 92.9% of its theoretical value, concurrently achieving a high energy density of 3702 Wh kg–1. This work paves the way for constructing durable AABs through an electrolyte regulation strategy.

Highly conductive hollow sandwich structure NC@SnO2@Fe2O3 composite with excellent lithium storage and cycling stability

High theoretical discharge capacity and environmental benignity of tin oxide and ferric oxide afforded many options for anode materials and attract lots of attention, while wide application was restricted by low electrical conductivity and structural instability of electrode material. To solve such problems, NC@SnO2@Fe2O3 nanorings were designed through simple hydrothermal method followed by carbonization of polydopamine. Herein, uniform distribution of all elements guaranteed the synergistic effect and enhanced conductivity, the rigid hollow sandwich structure greatly improved the stability of active substances, which will be conducive for extensive use of LIBs. When evaluated as lithium ion battery anodes, the discharge capacity of 748.2 mAh·g−1 of NC@SnO2@Fe2O3 nanorings was obtained at the current density of 400 mA·g−1.

Polyxylylviologen Chloride as an Organic Electrode Material for Efficient Reversible Chloride-Ion Storage

Organic molecules such as viologens with a nitrogen redox center show promise as efficient anion storage materials in rechargeable batteries. However, the high solubility of viologens in liquid electrolytes limits their wide electrochemical application. Herein, an insoluble polymerized polyxylylviologen chloride (PXVCl2) is first developed as a chloride ion storage electrode in chloride ion batteries. The as-prepared PXVCl2 electrode exhibits a competitive discharge capacity of 140 mA h g–1 (86% of the theoretical discharge capacity) compared to that of the previously reported organic conducting polymer electrodes. The incorporation of graphene in the PXVCl2 material achieves significant improvements in reaction reversibility and rate capability of the PXVCl2 electrode. Importantly, the nitrogen redox reactions based on chloride ion transfer of the PXVCl2 electrode are demonstrated.

Boosting discharge capability of α-Ni(OH)2 by cobalt doping based on robust spherical structure

α-Ni(OH)2 is a promising candidate of the currently commercialized β-Ni(OH)2 due to its higher theoretical discharge capacity in alkaline solution; however, its instability and poor conductivity plague the practical application. Herein, we propose α-Ni(OH)2 with Co doping and spherical structure to strengthen the stability and enhance the conductivity and use it as the cathode for nickel-metal hydride batteries. Studies show that proper Co doping promotes the electrochemical reaction between the active materials and the electrolyte due to the spherical α-Ni(OH)2 with enlarged interlayer distance and abundant hole channels, as well as high conductivity of Co, therefore, the obtained spherical α-Ni(OH)2 with 7 mol% Co doping delivers significantly improved discharge capability, which is 384.6 mAh g−1 at 70 mA g−1 (0.2 C), increased by 54.3 mAh g−1 compared with pure α-Ni(OH)2, and at a high current of 5 C, it still gives 269.4 mAh g−1, in contrast 218.5 mA g−1 for the pure α-Ni(OH)2. Besides, the cycling stability of the α-Ni(OH)2 with 7 mol% Co doping maintains 340 cycles at a capacity retention of 80% (1C), which is extended 110 cycles in contrast to the pure α-Ni(OH)2. These results provide the underpinning platform of α-Ni(OH)2 for battery applications with high discharge ability and cycle life.

Evaluation of Two-Electron Bispyridinylidene Anolytes and a TEMPO Catholyte for Non-Aqueous Redox Flow Batteries

All-organic, non-aqueous cells employing a 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) catholyte and two separate bispyridinylidene derivatives, one featuring a N,N′-propylene bridge and the other N,N′-di-n-propyl substituted, as anolyte-active materials have been investigated under static conditions in 0.8 M sodium tetrafluoroborate (NaBF4)/dimethylformamide (DMF) supporting electrolyte and an anion exchange membrane. Longer cycle life was achieved using the bridged bispyridinylidene (52 h/39 cycles to 50% theoretical discharge capacity, with E cell of 1.88 V) vs unbridged derivative (7 h/5 cycles to 50% theoretical discharge capacity, with E cell of 1.93 V). Based on stability tests conducted by NMR spectroscopy, both redox states (0/2+) for the two bispyridinylidene anolytes showed relatively high stability in the electrolyte, individually, which contrasts the poor cycling performance of their cells. A number of factors were identified that contributed to this including cross contamination through the membrane, the instability of TEMPO cation in the electrolyte, and the observation that the unbridged bispyridinylidene reacts with the corresponding bipyridinium redox partner over time in DMF. This work indicates the importance of having an alkyl bridge between pyridyl rings to support bispyridinylidene stability over cycling, and the need for more stable catholyte alternatives to TEMPO in DMF.

Further Improving Coulombic Efficiency and Discharge Capacity in LiNiO2 Material by Activating Sluggish ∼3.5 V Discharge Reaction.

The electrochemical activity of LiNiO2 at the initial cycle and factors affecting its activity were understood. Even though LiNiO2 can achieve almost theoretical charge capacity, it cannot deliver the theoretical discharge capacity that would result in low 1st Coulombic efficiency (CE). For different upper cut-off voltages at 4.3 and 4.1 V, the 1st CE barely increases. Given that the H2-H3 phase transition occurs at ∼4.2 V, the low 1st CE is not caused by this phase transition but is a result of the additional 3.5 V discharge reaction, which is kinetically limited and thereby not activated even at a reasonable current density. We found out that the several phase transitions during charge/discharge in LiNiO2 barely affect the 3.5 V reaction. Under galvanostatic intermittent titration technique (GITT) conditions, LiNiO2 can achieve ∼250 mAh/g of discharge capacity and 100% CE even with the 4.3 V cut-off voltage by fully activating the 3.5 V reaction. Using neutron diffraction and 6Li nuclear magnetic resonance (NMR) measurements, the sluggish kinetics of the 3.5 V reaction can be ascribed to difficult insertion of Li at the end of the discharge because this reaction can be accompanied by the rearrangement of cations or local structure change in the structure. To achieve high discharge capacity in LiNiO2 with the 4.3 V cut-off voltage, this 3.5 V sluggish reaction should be improved. The finding and understanding underlying the mechanism of the electrochemical activity will stimulate further research on high-capacity Ni-rich layered materials for high-performance Li-ion batteries.

Synthesis and investigation of a new organic electrode material based on condensation product of triquinoyl with 1,2,4,5-tetraaminobenzene

Abstract We report on the synthesis of PTTA that is a product of polymeric condensation of triquinoyl with 1,2,4,5-tetraaminobenzene and on the application of this polymer as the redox-active material for an electrode in lithium-ion batteries. Two electrolytes were selected: 1 M LiPF6 in ethylene carbonate : dimethyl carbonate mixture (1 : 1) and the same electrolyte with the additive of benzo-15-crown-5 (5 wt%). The new organic electrode has a theoretical capacity of 344 mAh g−1 (3e−), and its redox processes have been investigated using CV, charge-discharge cycling, and quantum-chemical modeling. It was shown that added benzo-15-crown-5 allows achieving the theoretical discharge capacity under the same conditions. Quantum chemical DFT modeling provided insights into the mechanistic aspects of PTTA metallation.

Probing and Interpreting the Porosity and Tortuosity Evolution of Li-O2 Cathodes on Discharge through a Combined Experimental and Theoretical Approach.

Li-O2 batteries offer a high theoretical discharge capacity due to the formation of light discharged species such as Li2O2, which fill the porous positive electrode. However, in practice, it is challenging to reach the theoretical capacity and completely utilize the full electrode pore volume during discharge. With the formation of discharge products, the porous medium evolves, and the porosity and tortuosity factor of the positive electrode are altered through shrinkage and clogging of pores. A pore shrinks as solid discharge products accumulate, the pore clogging when it is filled (or when access is blocked). In this study, we investigate the structural evolution of the positive electrode through a combination of experimental and computational techniques. Pulsed field gradient nuclear magnetic resonance results show that the electrode tortuosity factor changes much faster than suggested by the Bruggeman relation (an equation that empirically links the tortuosity factor to the porosity) and that the electrolyte solvent affects the tortuosity factor evolution. The latter is ascribed to the different abilities of solvents to dissolve reaction intermediates, which leads to different discharge product particle sizes: on discharging using 0.5 M LiTFSI in dimethoxyethane, the tortuosity factor increases much faster than for discharging in 0.5 M LiTFSI in tetraglyme. The correlation between a discharge product size and tortuosity factor is studied using a pore network model, which shows that larger discharge products generate more pore clogging. The Knudsen diffusion effect, where collisions of diffusing molecules with pore walls reduce the effective diffusion coefficients, is investigated using a kinetic Monte Carlo model and is found to have an insignificant impact on the effective diffusion coefficient for molecules in pores with diameters above 5 nm, i.e., most of the pores present in the materials investigated here. As a consequence, pore clogging is thought to be the main origin of tortuosity factor evolution.

A short review on dissolved lithium polysulfide catholytes for advanced lithium-sulfur batteries

Lithium-sulfur battery (LSB) technology has drawn enormous attention during the last decade. Benefitting from the high theoretical specific discharge capacity (1,675 mAh g−1) and energy density (2,600 Wh kg−1), LSBs have proved to be a suitable candidate for electric vehicles and large-scale power grid electrical energy storage systems. However, the commercialization of LSB is hindered by various barriers, which include the high insulating nature of sulfur and its discharge products, severe polysulfide shuttling phenomenon, extreme volume expansion during charging/discharging, and poor stability of Li metal anodes. Additionally, LSB technology faces considerable battery design challenges, which allows high sulfur content and/or sulfur-loading while simultaneously maintaining a low electrolyte/sulfur ratio. Therefore, in this review, we highlight recent effective strategies that lead to more practical and commercial LSBs. We restrict ourselves to various cathode architectures designed specifically to absorb dissolved polysulfide catholyte. The integration of dissolved lithium polysulfide catholyte with specially designed cathode substrates efficiently allows ultra-high sulfur loading and/or sulfur-content with low electrolyte/sulfur ratio while still exhibiting reasonable electrochemical performance and cycling stability. The effect of concentration variation of dissolved lithium polysulfide catholyte on the cell performance is also discussed in detail. Therefore, the present review encapsulates feasible strategies with practical parameters to address the problems associated with LSBs.

Suppress voltage decay of lithium-rich materials by coating layers with different crystalline states

Li-rich oxides are considered as the most commercial potential cathode materials due to the high theoretical specific discharge capacity. Here, ZrO2 in different crystalline states are applied as the coating layers to enhance the electrochemical performance of hollow Li[Li0.2Mn0.54Ni0.13Co0.13]O2 materials. Meanwhile, a series of characterizations (XRD, SEM, TEM, EDX etc.) are conducted to compare the effects of ZrO2 coating layer with different crystalline states on the host material. The results elucidate that the Li-rich Mn-based material with the polycrystal ZrO2 coating layer has a slight advantage in rate performance, while the host material with the single crystal ZrO2-coating layer has a better cycling performance and effectively suppresses voltage decay with the effect of excellently inhibiting layered to spinel-like phase transition and metal dissolution during charging and discharging process.

Synthesis and electrochemical characterization of 2D SnS2/RGO as anode material in sodium-ion batteries

Sodium ion batteries (SIB) have wide applications in the field of energy storage due to their low cost. Currently, due to its higher theoretical discharge capacity, tin and tin-based compounds are expected to become SIB anode materials. Here, 2D SnS2 nanosheets with thickness of about 20 nm loaded on reduced graphene oxide (RGO) material (SnS2/RGO) was synthesized by a hydrothermal method, which display superior properties. When the denseness of current is 100 m A/g, the discharge capacity of the first cycle is as high as 956.1 m Ah/g, and the initial Coulombic efficiency is up to 60.0%. From the third cycle to the 200th cycles, the capacity decline rate of each cycle is about 0.13%; after 200 cycles the discharge capacity is still 443.4 m Ah/g. This outstanding performance is ascribed to the composite structure of SnS2/RGO, which helps to alleviate the stress of volume change during sodium ion insertion and extraction and enhances the conductivity of the SnS2 material.

Catalytic Evaluation of Nanoflower Structured Manganese Oxide Electrocatalyst for Oxygen Reduction in Alkaline Media

An electrochemical nanoflowers manganese oxide (MnO2) catalyst has gained much interest due to its high stability and high specific surface area. However, there are a lack of insightful studies of electrocatalyst performance in nanoflower MnO2. This study assesses the electrocatalytic performances of nanoflower structure MnO2 for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in a zinc–air battery as a bifunctional electrocatalyst. The prepared catalyst was characterized in term of morphology, crystallinity, and total surface area. Cyclic voltammetry and linear sweep voltammetry were used to evaluate the electrochemical behaviors of the as-prepared nanoflower-like MnO2. The discharge performance test for zinc–air battery with a MnO2 catalyst was also conducted. The results show that the MnO2 prepared at dwell times of 2, 4 and 6 h were nanoflowers, nanoflower mixed with nanowires, and nanowires with corresponding specific surface areas of 52.4, 34.9 and 32.4 g/cm2, respectively. The nanoflower-like MnO2 catalyst exhibits a better electrocatalytic performance towards both ORR and OER compared to the nanowires. The number of electrons transferred for the MnO2 with nanoflower, nanoflower mixed with nanowires, and nanowire structures is 3.68, 3.31 and 3.00, respectively. The as-prepared MnO2 nanoflower-like structure exhibits the best discharge performance of 31% higher than the nanowires and reaches up to 30% of the theoretical discharge capacity of the zinc–air battery.

Synthesis of NiF2 and NiF2·4H2O Nanoparticles by Microemulsion and Their Self-Assembly.

Superstructures or self-assembled nanoparticles open the development of new materials with improved and/or novel properties. Here, we present nickel fluoride (NiF2) self-assemblies by successive preparatory methods. Originally, the self-assemblies were obtained by exploiting the water-in-oil microemulsion technique as a result of auto-organization of hydrated NiF2 (NiF2·4H2O) nanoparticles. The nanostructuration of NiF2·4H2O nanoparticles was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) data. The size and shape of NiF2·4H2O nanoparticles and their subsequent self-assemblies varied slightly as a function of water-to-surfactant and water-to-oil ratios. Scanning electron microscopy (SEM) and TEM characterizations revealed that the nanoparticles are organized into a succession of self-assemblies: from individual nanoparticles assembled into layers to truncated bipyramids, which further auto-organized themselves into almond-shaped superstructures. Anhydrous NiF2 was achieved by heating NiF2·4H2O self-assemblies under the dynamic flow of molecular fluorine (F2) at a moderate temperature (350 °C). Preservation of self-assemblies during the transformation from NiF2·4H2O to NiF2 is successfully achieved. The obtained materials have a specific surface area (SSA) of about 30 m2/g, more than 60% of that of bulk NiF2. The lithium-ion (Li+) storage capacities and the mechanism of the nanostructured samples were tested and compared with the bulk material by galvanostatic cycling and X-ray absorption spectroscopy (XAS). The nanostructured samples show higher capacities (∼650 mAh/g) than the theoretical (554 mAh/g) first discharge capacity due to the concomitant redox conversion mechanism of NiF2 and solid-electrolyte interphase (SEI) formation. The nanostructuration by self-assembly appears to positively influence the lithium diffusion in comparison to the bulk material. Finally, the magnetic properties of nanostructured NiF2·xH2O (x = 0 or 4) have been measured and appear to be very similar to those of the corresponding bulk materials, without any visible size reduction effect. The hydrated samples NiF2·4H2O show an antiferromagnetic ordering at TN = 3.8 K, whereas the dehydrated ones (NiF2) present a canted antiferromagnetic ordering at TN = 74 K.