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Lithium-ion batteries (LIBs) play an important role in modern society. The low capacity of graphite cannot meet the demands of LIBs calling for high power and energy densities. Silicon (Si) is one of the most promising materials instead of graphite, because of its high theoretical capacity, low discharge voltage, low cost, etc. However, Si shows low conductivity of both ions and electrons and exhibits a severe volume change during cycles. Fabricating nano-sized Si and Si-based composites is an effective method to enhance the electrochemical performance of LIB anodes. Using a small size of Si nanoparticles (SiNPs) is likely to avoid the cracking of this material. One critical issue is to disclose different types and electrochemical effects of various coupled materials in the Si-based composites for anode fabrication and optimization. Hence, this paper reviews diverse SiNP-based composites for advanced LIBs from the perspective of composition and electrochemical effects. Almost all kinds of materials that have been coupled with SiNPs for LIB applications are summarized, along with their electrochemical influences on the composites. The integrated materials, including carbon materials, metals, metal oxides, polymers, Si-based materials, transition metal nitrides, carbides, dichalcogenides, alloys, and metal-organic frameworks (MOFs), are comprehensively presented.

The surface microstructure of the current collectors significantly affects the electrochemical performance of lithium-ion batteries (LIBs). This study shows that an effective method of orthogonal p...

A conductive layer, made of multi-walled carbon nanotubes (MWCNTs), with micro-cracks and a micro/nano porous structure was fabricated between the active material layer (AML) and the current collector in this study. The coating thickness of MWCNTs-based conductive layer (MCL) varies in the range of 25-100 μm. The electrochemical tests of half-cells demonstrate that both the mesocarbon-microbeads (MCMB) anode and the LiCoO2 cathode with a micro-cracked MCL show higher capacity, lower impedance and less capacity fading. These improvements are closely due to the enhancement of adhesion strength, and also the outstanding buffer effect of the micro-cracked MCL. With the change of the coating thickness, the size and amount of the micro-cracks on the MCL varies accordingly to accommodate the active material with different particle sizes. The electrodes including a micro-cracked MCL with a coating thickness of 50 and 75 μm are more suitable for MCMB and LiCoO2 with a particle size of 10-20 μm.

This study presents a hierarchical MCMB/CuO/Cu anode structure with super-hydrophilic CuO substrate and blind-hole structures (BHSs) for lithium-ion battery (LIB) application. The porous hierarchical CuO clusters with controllable morphology and super hydrophilicity are prepared and combined with the BHSs on the surface of copper plates (CPs). Results indicate that the new anode yields a considerable improvement in reversible capacity and robustness under the condition of rate cycles. Compared with the conventional pattern of MCMB/Cu, the MCMB/CuO/Cu anode with BHSs produces reversible initial discharge and charge capacities of 381.5 and 347 mAh g−1 at a constant current of 0.5 mA. After 30 cycle times, the battery retains 276.7 and 276.6 mAh g−1, which amounts to 5 times as much as that of 0.5 C rate cycles. The energy density of the battery can be also greatly promoted. The larger surface area and porosity of the new anode facilitate formation of contact interface between the active material and current collector (CC). It also helps shorten the diffusion path of Li-ions and alleviate the volume expansion during the insertion and desertion processes of Li-ions.

Developing high-performance electrode structures is of great importance for advanced lithium-ion batteries. This study reports an efficient method to fabricate hierarchical shell/core CuO nanowire/carbon fiber composites via electroless plating and thermal oxidation processes. With this method, a binder-free CuO nanowire/carbon fiber shell/core hierarchical network composite anode for lithium-ion batteries is successfully fabricated. The morphology and chemical composition of the anode are characterized, and the electrochemical performance of the anode is investigated by standard electrochemical tests. Owing to the superior properties of carbon fibers and the morphological advantages of CuO nanowires, this composite anode still retains an excellent reversible capacity of 598.2 mAh g −1 with a capacity retention rate above 86%, even after 50 cycles, which is much higher than the CuO anode without carbon fibers. Compared to the typical CuO/C electrode systems, the novel binder-free anode yields a performance close to that of the typical core/shell electrode systems and a much higher reversible capacity and capacity retention than the similar shell/core patterns as well as the anodes with binders. It is believed that this novel anode will pave the way to the development of binder-free anodes in response to the increasing demands for high-power energy storage.

As environmentally friendly and high-energy density rechargeable energy storage devices, lithium-ion batteries (LIBs) have thriving prospects in the field of energy. The current collector, which serves as an important component of LIBs, significantly influences the electrochemical performance of the battery. Numerous efforts have been spent on the design and fabrication of high-performance negative current collectors in the field of LIBs to achieve excellent battery performances. These high-performance current collectors are mostly structuralized to achieve special functions. Hence, different types of structuralized current collectors used for LIB anodes are comprehensively discussed and summarized in this paper. The structuralized current collectors used in LIB anodes are classified into planar-plate-based special-surface current collectors and the 3D framework-based porous current collectors. Both types of the structuralized current collectors are further divided into the single-component and multicomponent current collectors. More subsections are provided and focus on providing description of the developing strategies, fabrication methods, electrochemical behaviors, in-depth reasons for high performances, and advantages and challenges for real applications of the structuralized current collectors in detail. Subsequently, the challenges and future research directions of structuralized anode current collectors are reasonably clarified. Based on an objective summary of the high-performance negative current collectors, this review provides an enlightening guide for the future development of current collectors and LIBs. The fundamental conclusions can also be extended to other energy storage devices.

Rechargeable lithium-ion battery (LIB) is a kind of electrochemical energy storage and conversion device with both high energy and power densities. The real application of various advanced LIBs (e.g., three-dimensional (3D) LIBs, flexible, wearable or customized LIBs) and integrated manufacturing of LIBs or LIB-powered devices depend on specific fabrication processes. However, conventional commercialized manufacturing techniques with sophisticated and expensive processes are far away from the facile, cost-effective and free-form fabrication demands. Additive manufacturing, usually known as 3D printing, is an ideal solution. This technology enables practical freedom of fabricating objects with well-controlled complex geometry through a layer-by-layer deposition process, independent of any templates. Almost all kinds of materials, from nanoscale to macroscale, can be used for 3D printing. In this work, we review the application advance of 3D printing in the field of LIBs. The fundamental concepts of representative 3D printing techniques are presented first, including the operation principles, requirements for raw printing materials and manufacturing accuracy of different 3D printing techniques. Then the applications are discussed at both component and package levels. Finally, the methodology, challenges and future perspectives of exploiting 3D printing for real applications in LIBs are presented. All the applications of 3D printing discussed herein can provide us with right directions of better energy conservation and conversion.