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Catalysts with two single-atom sites promote reversible conversion reactions between S and Li2S. The Co active site enhances the transformation kinetics of polysulfides upon charging, the Fe active site accelerates the transformation of Li2S to S8.

An artificial “salt-in-polymer” SEI was constructed on the surface of Li-MSiOx particles to maintain the structural integrity and inhibit the parasitic reaction at the electrode/electrolyte interface during cycling.

By applying a LiF-rich in situ solidified Li+-conductive interlayer, the interfacial contact and charge transfer stability between LPS and Li metal are notably improved, which leads to dendrite-free Li plating/stripping at the interface.

Phenolic resin as a typical hard carbon precursor has attracted much attention towards sodium-ion batteries (SIBs) due to its high carbon yield and large reversible capacity. However, phenolic resin-based hard carbon commonly suffers from limited cycling performance and low initial Coulombic efficiency. Herein, we synthesized a hard carbon material from phenolic resin and manipulated its microstructure through tuning the pyrolysis temperature and pre-oxidation procedure. In particular, hard carbon materials with pre-oxidation deliver much improved capacity retention in contrast with those without pre-oxidation. Further analysis shows that with the pre-oxidation procedure, the enlarged d002 spacing, the much disordered microstructure, and the increased content of oxygen-containing functional groups are responsible for the performance enhancement of hard carbon. This study provides an in-depth understanding of the microstructure feature of phenolic resin-based hard carbon and opens up a feasible avenue for the design of high-performance carbon anode materials for their application in SIBs.

Recycling of spent lithium-ion batteries has recently become a critical issue based on environmental concerns and a desire to reutilize resources. Among the existing recycling strategies, direct regeneration is largely encouraged from an economic and environmental perspective. However, current procedures used to separate the active cathode materials from the aluminum foil have some limitations for direct regeneration because they either destroy the structure of the cathode or use too many toxic and expensive reagents. Hence, we conducted comprehensive research on the microstructural evolution of the LiNi1−x−yCoxMnyO2 degraded electrode and then proposed a targeted method to recycle the spent cathode materials based on the increased residual lithium compounds. This separation process involves no other reagents but water, and toxic organic solvents, complicated processes, and waste treatments are unnecessary compared with the existing pretreatment strategies. Moreover, the separated cathodes are suitable for direct regeneration. Satisfactory capacity recovery of the cathode was achieved via simple sintering. Such a recycling process enables a sustainable closed-loop for the spent cathodes and provides new inspiration for the design of LIB recycling.

Chiral transcription from the molecular level to the macroscopic level by self-organization has been a topic of considerable interest for mimicking biological systems. Homochiral coordination polymers (CPs) are intriguing systems that can be applied in the construction of artificial helical architectures, but they have scarcely been explored to date. Herein, we propose a new strategy for the generation of superhelices of 1D CPs by introducing flexible cyclohexyl groups on the side chains to simultaneously induce interchain van der Waals interactions and chain misalignment due to conformer interconversion. Superhelices of S- or R-Tb(cyampH)3·3H2O (S-1H, R-1H) [cyampH2 = S- or R-(1-cyclohexylethyl)aminomethylphosphonic acid] were obtained successfully, the formation of which was found to follow a new type of “chain-twist-growth” mechanism that had not been described previously. The design strategy used in this work may open a new and general route to the hierarchical assembly and synthesis of helical CP materials., Superhelices of terbium phosphonates formed following a new type of “chain-twist-growth” mechanism involving flexible cyclohexyl groups.

Due to high ionic conductivity, favorable mechanical plasticity, and non-flammable properties, inorganic sulfide solid electrolytes bring opportunities to the practical realization of rechargeable lithium–metal batteries with high energy, yet their use was impeded by an electrochemically unstable Li–electrolyte interface. Herein, we propose to address the issue via a Li+-conductive gel polymer interlayer, which is derived in situ from a conventional liquid ether electrolyte during the cell fabrication process. The gel polymer interlayer not only enables intimate solid–solid contact and uniform Li-ion flux at the heterointerface but also effectively inhibits interfacial reactions and Li dendrite growth. With improved interfacial stability, a Li–Li symmetric cell with the gel polymer interlayer demonstrates an ultra-stable Li plating/stripping performance of over 1300 hours at 0.1 mA cm−2 and 350 hours at 0.5 mA cm−2 at room temperature, and a high critical current density of >5 mA cm−2. This work offers general insights into a reasonable design of an anode/electrolyte interface for high-energy rechargeable Li–metal batteries.

The capacity degradation mechanism of a spent LiFePO4 (LFP) cathode was investigated systematically and the occurrence of FePO4 in the cathode due to loss of Li+ was found to be mainly responsible for the short cycle life of LFP batteries. Given this, an easy, low-cost, and green cathode regeneration method was proposed. This work provides a new perspective for the recycling of spent batteries.

Energy storage is a vital issue to be solved for the efficient utilization of renewable energies such as solar, wind and tidal energy. In terms of rechargeable battery energy storage, magnesium has many advantages over lithium, such as low cost, environmental benignity and ease of operation. Therefore, rechargeable Mg batteries (RMBs) are considered as a promising green alternative to rechargeable lithium batteries for practical applications. Over the past few years, RMBs have made great progress, but there are also many problems. In this review, we summarize the latest developments of materials for RMBs from three main aspects: cathodes, electrolytes and anodes. The effects of cathode structures on Mg2+ ion migration kinetics are expounded; the properties and characteristics of various electrolytes for RMBs are briefly described; and the modification of metallic Mg and other types of anode materials are discussed comprehensively. In addition, the current challenges and several important guidelines for future progress of development of RMBs are also discussed.

The hierarchical electronic and ionic mixed conducting networks build in graphite felt electrodes possess excellent electrocatalytic activity and faster electronic and ionic conduction, resulting in an enhanced energy efficiency of vanadium redox flow batteries with durable life for 1000 cycles and a high discharge capacity of 10.1 A h L-1 at a current density of 350 mA cm-2.

With a remarkably high energy density and high safety, all-solid-state lithium–sulfur (ASSLS) batteries have emerged as promising next-generation energy storage systems. Direct tracking of the structural evolution at the solid–solid interfaces in an ASSLS battery is highly significant for deep understanding of the reaction mechanism to further improve the electrochemical performance. Herein, we present in situ monitoring of the evolution processes at both the cathode/electrolyte and anode/electrolyte interfaces in working ASSLS batteries via real-time optical microscope (OM) imaging. An irreversible transformation from bright-white to dark-brown in the polymer–ceramic composite electrolyte was directly captured upon discharge/charge, which indicates a shuttling process of polysulfides in the solid-state electrolyte further supported by XPS and Raman analyses. Furthermore, the in situ visualization of the temperature dependency of structural evolution clearly reveals that temperature greatly influences the polysulfide shuttling, irreversible volume-change of solid-state electrolytes and volume expansion of Li metal, which are directly correlated with the degradation of battery performance. These results provide a deep insight into the evolution processes of both structure and component in a working ASSLS battery, which could guide one to explore the electrochemical reactions at solid–solid interfaces and failure mechanism to design high performance lithium–sulfur batteries.

Rechargeable aqueous batteries are one of the most promising large-scale energy storage devices because of their environment-friendly properties and high safety advantages without using flammable and poisonous organic liquid electrolyte. In addition, rechargeable Zn–MnO2 batteries have great potential due to their low-cost resources as well as high energy density. However, dendritic growth of the zinc anode hinders the exertion of cycling stability and rate capacity in an aqueous Zn–MnO2 battery system. Here we use an electrochemical deposition method to in situ form a three-dimensional (3D) zinc anode on carbon fibers (CFs). This 3D Zn@CFs framework has lower charge transfer resistance with larger electroactive areas. Batteries based on the 3D zinc framework anode and α-MnO2 nanowire cathode present enhanced rate capacity and long cycling stability, which is promising for utilization in other zinc anode based aqueous batteries as an effective way to solve dendrite formation.

A novel Bi-based anode material with a stable alloy reaction is prepared by a solvothermal method. The Mg storage mechanism is elucidated for the first time. Owing to the space confinement of in situ conversion, the anode material shows superior magnesium storage performance, especially the cycling stability (capacity retention >96% after 100 cycles).

The phosphorus and fluorine codoped graphite felt electrodes with prominent hydrophilicity present excellent electroactivity towards V2+/V3+ and VO2+/VO2+, elevate the discharging ability up to 250 mA cm−2 and dramatically extend the energy efficiency of vanadium redox flow batteries towards 1000 cycles with 0.003% reduction per cycle.