Lithium-ion batteries (LIBs) possess several advantages over other types of viable practical batteries, including higher operating voltages, higher energy densities, longer cycle lives, lower rates of self-discharge and less environmental pollution Therefore, LIBs have been widely and successfully applied in portable electronic devices and industrial fields However, the rapidly increasing demands of new energy vehicles have also quickly increased the performance requirements of LIBs, including the need for higher power densities, greater capacity densities and better safety As battery designs gradually standardize, improvements in LIB performances mainly depend on the technical progress in key electrode materials such as positive and negative electrode materials, separators and electrolytes For LIB performances to meet the rising requirements, many studies on the structural characteristics and morphology modifications of electrode/separator/electrolyte materials with different synthesis methods have been conducted In this review, recent progress of LIBs is reviewed with a focus on positive electrode materials, negative electrode materials, separators and electrolytes in terms of energy density, power density, life-cycle and safety To accelerate the research and development and to overcome the challenges of LIB technology and application, several possible research directions are also discussed to further improve LIB performances

Recent progress in advanced electrode materials, separators and electrolytes for lithium batteries

The lithiation/delithiation in LiFePO4 is highly anisotropic with lithium-ion diffusion being mainly confined to channels along the b-axis. Controlling the orientation of LiFePO4 crystals therefore plays an important role for efficient mass transport within this material. We report here the preparation of single crystalline LiFePO4 nanosheets with a large percentage of highly oriented {010} facets, which provide the highest pore density for lithium-ion insertion/extraction. The LiFePO4 nanosheets show a high specific capacity at low charge/discharge rates and retain significant capacities at high C-rates, which may benefit the development of lithium batteries with both favorable energy and power density.

Single-Crystalline LiFePO4 Nanosheets for High-Rate Lithium Batteries

Recent progress of surface coating on cathode materials for high-performance lithium-ion batteries

Here, we introduce a new strategy using urea for the synthesis of carbon-incorporated 2D Fe3O4 (2D-Fe3O4/C) nanoflakes under solvothermal conditions with the following pyrolysis process under an inert atmosphere. Thanks to the structural advantages of 2D-Fe3O4/C, including 2D flakes providing a larger accessible surface area and exposing more active sites, as well as carbon incorporation promoting electrical conductivity for faster charge transfer, the 2D-Fe3O4/C displays a high specific capacitance of 386 F g−1 at 1 A g−1 in a three-electrode system. More importantly, when further assembled into a hybrid supercapacitor with pre-synthesized NiCo-layered double hydroxides as positive electrodes, the assembled supercapacitor device delivers a high-energy density of 32.5 W h kg−1 at 400 W kg−1 and little capacitance loss with bending angles ranging from 0° to 180°. As another capacitive application in desalination, 2D-Fe3O4/C also shows a high desalination capacity of 28.5 mg g−1 over 7.5 min, which suggests a very high mean desalination rate of 3.8 mg g−1 min−1. Our results not only highlight the significance of 2D metal oxide nanosheets/nanoflakes, but also hold great potential for high-performance capacitive applications in supercapacitors and desalination.

https://pubs.rsc.org/en/content/articlepdf/2021/QM/D0QM00946F

Carbon-incorporated Fe3O4 nanoflakes: high-performance faradaic materials for hybrid capacitive deionization and supercapacitors

Lithium-ion batteries (LIBs) have been widely used in many fields such as portable electronics and electric vehicles since their successful commercialization in the 1990s. However, the electrochemical performance of current commercial LIBs still needs to be further improved to meet the continuously increasing demands for energy storage applications. Recently, tremendous research efforts have been made in developing next-generation LIBs with enhanced electrochemical performance. In this review, we mainly focus on the recent progress of LIBs with high electrochemical performance from four aspects, including cathode materials, anode materials, electrolyte, and separators. We discuss not only the commercial electrode materials (LiCoO2, LiFePO4, LiMn2O4, LiNi x Mn y Co z O2, LiNi x Co y Al z O2, and graphite) but also other promising next-generation materials such as Li-, Mn-rich layered oxides, organic cathode materials, Si, and Li metal. For each type of materials, we highlight their problems and corresponding strategies to enhance their electrochemical performance. Nowadays, one of the key challenges to construct high-performance LIBs is how to develop cathode materials with high capacity and working voltage. This review provides an overview and future perspectives to develop next-generation LIBs with high electrochemical performance.

Recent progress on lithium-ion batteries with high electrochemical performance

Fe3O4@C nanoparticles with a 3D net-like structure were synthesized via a facile and scalable one-pot co-precipitation followed by a subsequent carbonization in an Ar atmosphere. Verified by scanning and transmission electron microscopy characterization, it can be seen that Fe3O4 nanoparticles with the size of 10–15 nm were embedded in a uniform carbon shell with a thickness of around 2 nm. Furthermore, the corresponding XRD and EDS analysis combined with TEM images also proved that the thin carbon layer on the nano-scale Fe3O4 was amorphous. The charge/discharge tests showed that Fe3O4@C composite delivered an excellent reversible capacity of 980 mAh g−1 after 100 cycles at a current density of 92.4 mA g−1, which was much higher than that of the pure Fe3O4 (170 mAh g−1) synthesized by the same method. The outstanding reversible capacity is attributed to the small size of Fe3O4 particles and the high conductivity and mechanical strength of the amorphous carbon layer, which accelerates the electron transfer and relieves structure collapse caused by mechanical stress, thus maintaining a superior electrochemical stability.

One-pot co-precipitation synthesis of Fe 3 O 4 nanoparticles embedded in 3D carbonaceous matrix as anode for lithium ion batteries

Enhanced performance of LiFePO4 originating from the synergistic effect of graphene modification and carbon coating

Hydrothermal synthesis of red phosphorus @reduced graphene oxide nanohybrid with enhanced electrochemical performance as anode material of lithium-ion battery

A covalent linkage between polyaniline (PANI) and Si nanoparticles in PANI-encapsulated Si nanocomposites was proposed and achieved by a facile and economical synthetic strategy, in which NH2-graft...

PANI-Encapsulated Si Nanocomposites with a Chemical Bond Linkage in the Interface Exhibiting Higher Electrochemical Stability as Anode Materials for Lithium-Ion Batteries

Recrystallization synthesis of disodium rhodizonate-conductive polyaniline composite with high cyclic performance as cathode material of sodium-ion battery

Jian Xiong

Papers

One-pot co-precipitation synthesis of Fe 3 O 4 nanoparticles embedded in 3D carbonaceous matrix as anode for lithium ion batteries

Enhanced performance of LiFePO4 originating from the synergistic effect of graphene modification and carbon coating

Hydrothermal synthesis of red phosphorus @reduced graphene oxide nanohybrid with enhanced electrochemical performance as anode material of lithium-ion battery

PANI-Encapsulated Si Nanocomposites with a Chemical Bond Linkage in the Interface Exhibiting Higher Electrochemical Stability as Anode Materials for Lithium-Ion Batteries

Recrystallization synthesis of disodium rhodizonate-conductive polyaniline composite with high cyclic performance as cathode material of sodium-ion battery