Conspectus All-solid-state lithium batteries have received considerable attention in recent years with the ever-growing demand for efficient and safe energy storage technologies. However, key issues remain unsolved and hinder full-scale commercialization of all-solid-state lithium batteries. Previously, most discussion only focused on how to achieve high energy density from the theoretical perspective. Herein, we analyze the real cases of different kinds of all-solid-state lithium batteries with high energy density to understand the current status, including all-solid-state lithium-ion batteries, all-solid-state lithium metal batteries, and all-solid-state lithium–sulfur batteries. First, we propose a general calculation method to visually compare the above battery systems partly due to no normative parameters for solid-state batteries. After then, we discuss and interpret the key parameters and current situation of all-solid-state lithium batteries. Through the summary and analysis of the frontier, one can find that, although some breakthrough has been made in energy density and areal capacity for solid-state batteries, there are still many aspects to be improved such as power density and rate performance. Therefore, in response to the challenges, we propose possible directions for future development, including the ways to prepare different kinds of solid electrolyte films to reduce the proportion of inactive substances in the cell. The advantages and disadvantages are discussed about three typical solid-state electrolyte films (inorganic solid electrolyte, solid polymer electrolyte, and composite solid electrolyte). In addition, potential candidate anodes with high capacity and cathodes with high voltage and/or high capacity are also discussed in details. The combination of lithium metal anodes with ultrahigh capacity and cathodes with both high capacity and high voltage is the current mainstream direction. However, the interface problems have become the most pressing factor on the application. Therefore, we introduce the origin of interfaces and interphases and discuss how to build a stable electrode/solid electrolyte interface. One thing is clear that artificial solid electrolyte interphases and composite solid electrolytes are effective to obtain stable anode/solid electrolyte interfaces, which can prevent lithium from constantly reacting with solid electrolytes, ensure the uniform lithium deposition and prevent the formation of lithium dendrites. For the cathode/solid electrolyte interface, reasonable composite cathodes, multilayer design, and composite solid electrolytes can optimize the electrode and interface for stable cycles at high voltages and high current densities. Furthermore, the contribution of high-throughput computations and machine learning is introduced in accelerating materials screening and development. Among them, progress has been made in solid electrolytes and artificial solid electrolyte interphases through materials genome engineering and machine learning. Finally, we provide some out...

A major problem against the realization of high energy density and safe solid Li-ion batteries lies in detrimental reactions at the interface between the lithium anode and the solid electrolytes.

Non-uniform plating-stripping behaviours of Li metal anodes hinder the application of Li-based batteries with high energy density. Here, a stable 3D matrix is designed by coating carbon skeleton with MXene,...

The main bottleneck against industrial utilization of sodium ion batteries (SIBs) is the lack of high‐capacity electrodes to rival those of the benchmark lithium ion batteries (LIBs). Here in this work, we have developed an economical method for in situ fabrication of nanocomposites made of crystalline few‐layer graphene sheets loaded with ultrafine SnO2 nanocrystals, using short exposure of microwave to xerogel of graphene oxide (GO) and tin tetrachloride containing minute catalyzing dispersoids of chemically reduced GO (RGO). The resultant nanocomposites (SnO2@MWG) enabled significantly quickened redox processes as SIB anode, which led to remarkable full anode‐specific capacity reaching 538 mAh g−1 at 0.05 A g−1 (about 1.45 times of the theoretical capacity of graphite for the LIB), in addition to outstanding rate performance over prolonged charge–discharge cycling. Anodes based on the optimized SnO2@MWG delivered stable performance over 2000 cycles even at a high current density of 5 A g−1, and capacity retention of over 70.4% was maintained at a high areal loading of 3.4 mg cm−2, highly desirable for high energy density SIBs to rival the current benchmark LIBs.

It is of great importance to develop high‐capacity electrodes for sodium‐ion batteries (SIBs) using low‐cost and abundant materials, so as to deliver a sustainable technology as alternative to the established lithium‐ion batteries (LIBs). Here, a facile ball milling process to fabricate high‐capacity SIB anode is devised, with large amount of amorphous SeP being loaded in a well‐connected framework of high‐conductivity crystalline graphene (HCG). The HCG substrate enables fast transportation of Na ions and electrons, while accommodating huge volumetric changes of the active anode matter of SeP. The strong glass forming ability of NaxSeP helps prevent crystallization of all stable compounds but ultrafine nanocrystals of Na2Se and Na3P. Thus, the optimized anode delivers excellent rate performance with high specific capacities being achieved (855 mAh g−1 at 0.2 A g−1 and 345 mAh g−1 at 5 A g−1). More importantly, remarkable cycling stability is realized to maintain a steady capacity of 732 mAh g−1 over 500 cycles, when the SeP in the SeP@HCG still remains 86% of its theoretical capacity. A high areal capacity of 2.77 mAh is achieved at a very high loading of 4.1 mg cm−2 anode composite.