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Despite their conspicuous advantages in energy density, lithium metal batteries (LMBs) are still in the research stage owing to uncontrolled lithium dendrite growth, which deteriorates their cycle ...

An all-solid-state battery with a lithium metal anode is a strong candidate for surpassing conventional lithium-ion battery capabilities. However, undesirable Li dendrite growth and low Coulombic efficiency impede their practical application. Here we report that a high-performance all-solid-state lithium metal battery with a sulfide electrolyte is enabled by a Ag–C composite anode with no excess Li. We show that the thin Ag–C layer can effectively regulate Li deposition, which leads to a genuinely long electrochemical cyclability. In our full-cell demonstrations, we employed a high-Ni layered oxide cathode with a high specific capacity (>210 mAh g−1) and high areal capacity (>6.8 mAh cm−2) and an argyrodite-type sulfide electrolyte. A warm isostatic pressing technique was also introduced to improve the contact between the electrode and the electrolyte. A prototype pouch cell (0.6 Ah) thus prepared exhibited a high energy density (>900 Wh l−1), stable Coulombic efficiency over 99.8% and long cycle life (1,000 times). Solid-state Li metal batteries represent one of the most promising rechargeable battery technologies. Here the authors report an exceptional high-performance prototype solid-state pouch cell made of a sulfide electrolyte, a high-Ni layered oxide cathode and, in particular, a silver–carbon composite anode with no excess Li.

The development of high-performance all-solid-state lithium-ion batteries depends on the realization of solid-state electrolytes with high ionic conductivity. In this study, halogen-rich argyrodites with high ionic conductivities were fabricated, and their structural evolution was studied. In addition, the optimum heat treatment protocol for enhancing the ionic conductivity of halogen-rich argyrodites (Li5.3PS4.3Cl1.7) was determined by interpreting the reaction mechanism. Structural and thermal analyses revealed that fast heating results in the formation of intermediates containing PS43- units and Cl- ions, which remain in the material and decrease the ionic conductivity (~1.6 mS/cm at 25 °C). Surprisingly, slow heating, such as step heating, can promote the slow reaction that produces argyrodite from an intermediate, resulting in a high ionic conductivity (~5.0 mS/cm at 25 °C). Furthermore, we examined the performance of all-solid-state batteries assembled with Li5.3PS4.3Cl1.7 as a solid-state electrolyte and found that the batteries employing Li5.3PS4.3Cl1.7 treated by a slow heating protocol performs better than the batteries employing Li5.3PS4.3Cl1.7 treated by a fast heating protocol, with an impressive specific capacity of 151.8 mAh/g at 1.0 C. Herein, we assert that further developing halogen-rich argyrodites as glass-ceramics may provide a long-sought solution to realizing ASSBs capable of achieving a high rate.

Although anomalous melt properties have been attributed to the presence of triply coordinated oxygen ([3]O), the presence of [3]O in covalent amorphous oxides has not been revealed experimentally; such verification is the Holy Grail in the study of the physics and chemistry of glasses. We report the first 17O NMR spectrum for amorphous Al2O3 and reveal the hidden nature of [3]O. The detailed NMR characteristics of the oxygen tricluster are distinct from those estimated for the crystalline analogs, thus indicating its unique structure. This unambiguous evidence of the presence of [3]O allows us to microscopically constrain its glass-forming ability and unique two-step crystallization paths of amorphous Al2O3 through the annihilation of glassy [3]O with multiple [5]Al species.

A lithium (Li) metal anode is required to achieve a high-energy-density battery, but because of an undesirable growth of Li dendrites, it still has safety and cyclability issues. In this study, we have developed a microsphere-protected (MSP) Li metal anode to suppress the growth of Li dendrites. Microspheres could guide Li ions to selective areas and pressurize dendrites during their growth. Interconnections between microspheres improved the pressurization. By using an MSP Li metal anode in a 200 mAh pouch-type Li/NCA full cell at 4.2 V, dendrite-free Li deposits with a density of 0.4 g/cm3, which is 3 times greater than that in the case of bare Li metal, were obtained after charging at 2.9 mAh/cm2. The MSP Li metal enhanced the cyclability to 190 cycles with a criterion of 90% capacity retention of the initial discharge capacity at a current density of 1.45 mA/cm2.

Lithium (Li) metal has received much attention as a promising anode candidate in recent years with the increasing demand for high-energy-density rechargeable batteries in industrial fields. However, unlike current graphite anodes where Li ions are intercalated, metallic Li anodes generate Li deposition forming an uneven anode surface and have high reactivity toward organic electrolytes. This can cause safety concerns including cycling instability. Thus, developing a stable electrolyte and its corresponding separator is widely recognized as a major challenge to the practical application of Li metal batteries. Although there remains a need for improving the separator performance because of poor separator wettability for highly viscous electrolytes, little work has been done about the separator structure design to ensure proper wettability and stability [1]. In this study, we propose a high performance composite coated separator for Li metal batteries. A commercial separator was thinly coated with a mixture of block copolymer, ionic liquid, and microspheres. The composite electrolyte coated separator showed significantly enhanced wettability which is sufficient to adsorb highly viscous electrolytes. To improve the mechanical properties of the separator, microspheres with high rigidity and stability to organic electrolyte [2] were used. The tensile strength and thermal stability of the separator were improved by microspheres and block copolymer. This approach appears to be effective in improving battery safety by inhibiting the growth of Li dendrites. Due to the increased wettability and enhanced mechanical properties, the cycle life of the cell was greatly improved when our separator was applied. In addition, unlike the ceramic component with a poor dispersion in the coating solution, our novel coating blend enables cost-effective production with rapid and uniform coatings with its excellent dispersion stability. [1] M. H. Ryou, Y. M. Lee, J. K. Park, and J. W. Choi, Adv. Mater., 23, 27 (2011). [2] Y. G. Lee, S. Ryu, T. Sugimoto, T. Yu, W. S. Chang, Y. Yang, C. Jung, J. Woo, S. G. Kang, H. N. Han, S. G Doo, Y. Hwang, H. Chang, J. M. Lee, and J. Y. Sun, Chem. Mater., 29, 14 (2017).

In order to have better insights into the chemical differentiation of Earth from its magma ocean phase to the current stratified structure, detailed information of crystallization kinetics of silicate melts consisting of the magma ocean is essential. The structural transitions in oxide glasses and melts upon crystallization provide improved prospects for a systematic and quantitative understanding of the crystallization processes. Here, we report the 3QMAS NMR spectra for sol-gel synthesized glass with varying temperature and annealing time. The NMR spectra for the amorphous show well-resolved Al coordination environments, characterized with mostly and a minor fraction of . The fraction of in the alumina phase decreases with increasing annealing time at constant temperature. The NMR results of phases also imply that multiple processes (e.g., crystallization and/or changes in structural disorder within glasses) could involve upon its phase transition. The current results and method can be useful to understand crystallization kinetics of diverse natural and multi-component silicate glasses and melts. The potential result may yield atomic-level understanding of Earth`s chemical evolution and differentiation from the magma ocean.