Search

All‐solid‐state lithium batteries (ASSLBs) based on sulfide solid electrolytes (SEs) are one of the most promising strategies for next‐generation energy storage systems and electronic devices. However, the poor chemical/electrochemical stability of sulfide SEs with oxide cathode materials and high interfacial impedance, particularly due to physical contact failure, are the major limiting factors to the development of sulfide SEs in ASSLBs. Herein, the composite cathode of MOF‐derived Fe7S8@C and Li6PS5Br fabricated by an infiltration method (IN–Fe7S8) with dissoluble sulfide electrolyte (dissoluble SE) is reported. Dissoluble SE can easily infiltrate the porous sheet‐type Fe7S8@C cathode to homogeneously contact with Fe7S8 nanoparticles that are embedded in the surrounding carbon matrixes and form a fast ionic transport network. Benefiting from applying dissoluble SE and Fe7S8@C, the IN‐Fe7S8‐based cells displayed a reversible capacity of 510 mAh g−1 after 180 cycles at 0.045 mA cm−2 at 30 °C. This work demonstrates a novel and practical method for the development of high‐performance all‐sulfide‐based solid state batteries. [ABSTRACT FROM AUTHOR]

All‐solid‐state batteries (ASSBs) based on inorganic solid electrolytes (SEs) are one of the most promising strategies for next‐generation energy storage systems and electronic devices due to the higher energy density and intrinsic safety. However, the poor solid‐solid contact and restricted chemical/electrochemical stability of inorganic SEs both in cathode and anode SE interfaces cause contact failure and the degeneration of SEs during prolonged charge‐discharge processes. As a result, the increasing interface resistance significantly affects the coulombic efficiency and cycling performance of ASSBs. Herein, we present a fundamental understanding of physical contact and chemical/electrochemical features of ASSB interfaces based on mainstream inorganic SEs and summarize the recent work on interface modification. SE doping, optimizing morphology, introducing interlayer/coating layer, and utilizing compatible electrode materials are the key methods to prevent side reactions, which are discussed separately in cathode/anode‐SE interface. We also highlight the constant extra stack pressure applied during ASSB cycling, which is important to the electrochemical performance. Finally, our perspectives on interface modification for practical high‐performance ASSBs are put forward. [ABSTRACT FROM AUTHOR]

Secondary batteries have been widespread in the daily life causing an ever-growing demand for long-cycle lifespan and high-energy alkali-ion batteries. As an essential constituent part, electrode materials with superior electrochemical properties play a vital role in the battery systems. Here, an outstanding electrode of yolk-shell ZnS@C nanorods is developed, introducing considerable void space via a self-sacrificial template method. Such carbon encapsulated nanorods moderate integral electronic conductivity, thus ensuring rapid alkali-ions/electrons transporting. Furthermore, the porous structure of these nanorods endows enough void space to mitigate volume stress caused by the insertion/extraction of alkali-ions. Due to the unique structure, these yolk-shell ZnS@C nanorods achieve superior rate performance and cycling performance (740 mAh g-1 at 1.0 A g-1 after 540 cycles) for lithium-ion batteries. As a potassium-ion batteries anode, they achieve an ultra-long lifespan delivering 211.1 mAh g-1 at 1.0 A g-1 after 5700 cycles. The kinetic analysis reveals that these ZnS@C nanorods with considerable pseudocapacitive contribution benefit the fast lithiation/delithiation. Detailed transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses indicate that such yolk-shell ZnS@C anode is a typical reversible conversion reaction mechanism accomplished by alloying processes. This rational design strategy opens a window for the development of superior energy storage materials. [ABSTRACT FROM AUTHOR]

For the past few years, a new generation of energy storage systems with large theoretical specific capacity has been urgently needed because of the rapid development of society. Lithium–sulfur (Li−S) batteries are regarded as one of the most promising candidates for novel battery systems, since their resurgence at the end of the 20th century Li−S batteries have attracted ever more attention, attributed to their notably high theoretical energy density of 2600 W h kg−1, which is almost five times larger than that of commercial lithium‐ion batteries (LIBs). One of the determining factors in Li−S batteries is how to design/prepare the sulfur cathode. For the sulfur host, the major technical challenge is avoiding the shuttling effect that is caused by soluble polysulfides during the reaction. In past decades, though the sulfur cathode has developed greatly, there are still some enormous challenges to be conquered, such as low utilization of S, rapid decay of capacity, and poor cycle life. This article spotlights the recent progress and foremost findings in improving the performance of Li−S batteries by employing multifunctional metal phosphides as host materials. The current state of development of the sulfur electrode of Li−S batteries is summarized by emphasizing the relationship between the essential properties of metal phosphide‐based hybrid nanomaterials, the chemical reaction with lithium polysulfides and the latter′s influence on electrochemical performance. Finally, trends in the development and practical application of Li−S batteries are also pointed out. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries have ultra–high energy density and are considered to be one of the most promising energy storage systems among all battery systems. However, due to various thorny problems, their commercial production has not yet been realized. The current experimental research normally lacks a systematic investigation into the conversion mechanism of the sulfur cathode from the electronic structure level. Actually, there is still a lack of powerful theoretical guidance for the design of high–performance Li–S batteries and the selection of modified materials still seems blind. In this article, with the chelated Fe‐polyvinyl pyrrolidone as the precursor, a series of Fe–based materials (e.g., Fe3O4@C, FeS@C, Fe3N@C) are synthesized as modified layers for battery separators, and the performance differences between them are systematically studied. It is found that the d–p band center model developed based on the d band center can reasonably combine the reaction potential of Li2S4 and performance differences. Simultaneously, the interaction between Li2S6 and the adsorption interface is simulated by ab initio molecular dynamics. This current work sheds light on promising material design for superior Li–S batteries both from a theoretical and experimental perspective. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries (SIBs) have attracted much attention due to their abundance, easy accessibility, and low cost. All of these advantages make them potential candidates for large‐scale energy storage. The P2‐type layered transition‐metal oxides (NaxTMO2; TM=Mn, Co, Ni, Ti, Fe, V, Cr, and a mixture of multiple elements) exhibit good Na+ ion conductivity and structural stability, which make them an excellent choice for the cathode materials of SIBs. Herein, the structural evolution, anionic redox reaction, some challenges, and recent progress of NaxTMO2 cathodes for SIBs are reviewed and summarized. Moreover, a detailed understanding of the relationship of chemical components, structures, phase compositions, and electrochemical performance is presented. This Review aims to provide a reference for the development of P2‐type layered transition‐metal oxide cathode materials for SIBs. [ABSTRACT FROM AUTHOR]