Qidong Li

NiSe2 Nanooctahedra as an Anode Material for High-Rate and Long-Life Sodium-Ion Battery

In this article, we report NiSe2 nanooctahedra as a promising anode material for sodium-ion batteries (SIBs). They exhibit outstanding long-term cyclic stability (313 mAh/g after 4000 cycles at 5 A/g) and excellent high-rate capability (175 mAh/g at 20 A/g). Besides, the initial Coulombic efficiency of NiSe2 is also very impressive (over 90%). Such remarkable performances are attributed to good conductivity, structural stability, and the pseudocapacitive behavior of the NiSe2. Furthermore, the sodium ion storage mechanism of NiSe2 is first investigated by in situ XRD and ex situ XRD. These highlights give NiSe2 a competitive strength for rechargeable SIBs.

Self-template synthesis of hollow shell-controlled Li3VO4 as a high-performance anode for lithium-ion batteries

A hollow shell-controlled Li3VO4 is fabricated via a facile self-template method, which has a controllable shell thickness in the range of 10–300 nm. This hollow shell-controlled Li3VO4 composited with reduced graphene oxide exhibits excellent rate capability (201 mA h g−1 at 125 C) and superior high-temperature stability (364.2 mA h g−1 after 1000 cycles at 10 C, 60 °C).

Nitrogen-self-doped carbon with a porous graphene-like structure as a highly efficient catalyst for oxygen reduction

A non-noble metal nitrogen (N)-doped carbon catalyst, with a porous graphene-like structure, is prepared by pyrolyzing polyaniline with addition of urea. Herein, urea not only serves as a N source similar to polyaniline by incorporating N atoms into the carbon matrix, but plays a key role in forming the porous graphene-like structured carbon nanosheet. The electrochemical characterization shows that the prepared catalyst with a unique graphene-like structure exhibits an oxygen reduction reaction (ORR) activity that outperforms that of the commercial Pt/C catalyst in alkaline media, its half-wave potential nearly 30 mV more positive than Pt/C, and both superior stability and fuel (methanol and CO) tolerance to Pt/C. Significantly, such a catalyst also exhibits a good ORR activity which is comparable to Pt/C, as well as a higher stability than Pt/C in acidic media.

Pseudocapacitive titanium oxynitride mesoporous nanowires with iso-oriented nanocrystals for ultrahigh-rate sodium ion hybrid capacitors

Titanium oxynitride mesoporous nanowires (Ti(O,N)-MP-NWs) composed of iso-oriented interconnected nanocrystals with [100] preferred orientation and tunable O/N ratios are synthesized, based on an anion exchange process. By investigating the electrochemical performance, it is found to exhibit high pseudocapacitive sodium storage performance, demonstrated by kinetic analysis and experimental characterizations. Subsequently, the assembled asymmetric hybrid sodium ion capacitor (AC//Ti(O,N)) exhibits high energy and power densities. Our work proposes the high pseudocapacitance in non-aqueous sodium ion system is very promising for high-power and low-cost energy storage applications.

Metastable amorphous chromium-vanadium oxide nanoparticles with superior performance as a new lithium battery cathode

AbstractThe main drawbacks of vanadium oxide as a cathode material are its low conductivity, low practical capacity and poor cycling stability. Adding Cr can improve its conductivity and a metastable amorphous state may provide higher capacity and stability. In this work, metastable amorphous Cr-V-O nanoparticles have been successfully prepared through a facile co-precipitation reaction followed by annealing treatment. As a cathode material for lithium batteries, the metastable amorphous Cr-V-O nanoparticles exhibit high capacity (260 mAh/g at 100 mA/g between 1.5–4 V), low capacity loss (more than 80% was retained after 200 cycles at 100 mA/g) and high rate capability (up to 3 A/g).

Multidimensional Synergistic Nanoarchitecture Exhibiting Highly Stable and Ultrafast Sodium‐Ion Storage

Conversion-type anodes with multielectron reactions are beneficial for achieving a high capacity in sodium-ion batteries. Enhancing the electron/ion conductivity and structural stability are two key challenges in the development of high-performance sodium storage. Herein, a novel multidimensionally assembled nanoarchitecture is presented, which consists of V2 O3 nanoparticles embedded in amorphous carbon nanotubes that are then coassembled within a reduced graphene oxide (rGO) network, this materials is denoted V2 O3 ⊂C-NTs⊂rGO. The selective insertion and multiphase conversion mechanism of V2 O3 in sodium-ion storage is systematically demonstrated for the first time. Importantly, the naturally integrated advantages of each subunit synergistically provide a robust structure and rapid electron/ion transport, as confirmed by in situ and ex situ transmission electron microscopy experiments and kinetic analysis. Benefiting from the synergistic effects, the V2 O3 ⊂C-NTs⊂rGO anode delivers an ultralong cycle life (72.3% at 5 A g-1 after 15 000 cycles) and an ultrahigh rate capability (165 mAh g-1 at 20 A g-1 , ≈30 s per charge/discharge). The synergistic design of the multidimensionally assembled nanoarchitecture produces superior advantages in energy storage.

Pseudocapacitive layered birnessite sodium manganese dioxide for high-rate non-aqueous sodium ion capacitors

Layered transition metal oxides are promising cathodes for sodium ion capacitors due to their high specific capacity. In this work, we present a layered birnessite sodium manganese dioxide (Na0.77MnO2·0.5H2O) supported by a two-dimensional conductive network (denoted as b-NMO/C) as a cathode for non-aqueous sodium ion capacitor (SIC). The interlayer crystal water and carbon networks promote the ion/electron transport kinetics and overcome the structural instability, leading to largely enhanced electrochemical performance. As a result, the as-synthesized b-NMO/C cathode delivers a capacity of 192 mA h g−1 at 0.25C and 43 mA h g−1 even at a high rate of 100C. The attained performance is compared favorably with those of state-of-the-art Mn-based cathodes for sodium ion storage. Furthermore, the assembled asymmetric SIC (b-NMO/C//graphite) exhibits the highest energy (91 W h kg−1 achieved at ∼84 W kg−1) and power (5816 W kg−1 achieved at ∼37 W h kg−1) densities within the voltage range of 0.5–3.8 V.

Heterostructured Bi2S3–Bi2O3 Nanosheets with a Built-In Electric Field for Improved Sodium Storage

Constructing novel heterostructures has great potential in tuning the physical/chemical properties of functional materials for electronics, catalysis, as well as energy conversion and storage. In this work, heterostructured Bi2S3-Bi2O3 nanosheets (BS-BO) have been prepared through an easy water-bath approach. The formation of such unique BS-BO heterostructures was achieved through a controllable thioacetamide-directed surfactant-assisted reaction process. Bi2O3 sheets and Bi2S3 sheets can be also prepared through simply modifying the synthetic recipe. When employed as the sodium-ion battery anode material, the resultant BS-BO displays a reversible capacity of ∼630 mA h g-1 at 100 mA g-1. In addition, the BS-BO demonstrates improved rate capability and enhanced cycle stability compared to its Bi2O3 sheets and Bi2S3 sheets counterparts. The improved electrochemical performance can be ascribed to the built-in electric field in the BS-BO heterostructure, which effectively facilitates the charge transport. This work would shed light on the construction of novel heterostructures for high-performance sodium-ion batteries and other energy-related devices.

Sodium Ion Capacitor Using Pseudocapacitive Layered Ferric Vanadate Nanosheets Cathode

Summary Sodium ion capacitors (SICs) are designed to deliver both high energy and power densities at low cost. Electric double-layer capacitive cathodes are typically used in these devices, but they lead to very limited capacity. Herein, we apply a pseudocapacitive layered ferric vanadate (Fe-V-O) as cathode to construct non-aqueous SICs with both high energy and power densities. The Fe-V-O nanosheets cathode displays remarkable rate capability and cycling stability. The pseudocapacitive sodium storage mechanism of Fe-V-O, with over 83% of total capacity from capacitive contribution, is confirmed by kinetics analysis and ex situ characterizations. The capacitive-adsorption mechanism of hard carbon (HC) anode is demonstrated, and it delivers excellent rate capability. Based on as-synthesized materials, the assembled HC//Fe-V-O SIC delivers a maximum energy density of 194 Wh kg−1 and power density of 3,942 W kg−1. Our work highlights the advantages of pseudocapacitive cathodes for achieving both high energy and power densities in sodium storage devices.

Graphene oxide-decorated Fe2(MoO4)3 microflowers as a promising anode for lithium and sodium storage

Mixed transition metal oxides (MTMOs) have received intensive attention as promising anode materials for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). In this work, we demonstrate a facile one-step water-bath method for the preparation of graphene oxide (GO) decorated Fe2(MoO4)3 (FMO) microflower composite (FMO/GO), in which the FMO is constructed by numerous nanosheets. The resulting FMO/GO exhibits excellent electrochemical performances in both LIBs and SIBs. As the anode material for LIBs, the FMO/GO delivers a high capacity of 1,220 mAh·g–1 at 200 mA·g–1 after 50 cycles and a capacity of 685 mAh·g–1 at a high current density of 10 A·g–1. As the anode material for SIBs, the FMO/GO shows an initial discharge capacity of 571 mAh·g–1 at 100 mA·g–1, maintaining a discharge capacity of 307 mAh·g–1 after 100 cycles. The promising performance is attributed to the good electrical transport from the intimate contact between FMO and graphene oxide. This work indicates that the FMO/GO composite is a promising anode for high-performance lithium and sodium storage.