Intercepting Dendrite Growth With a Heterogeneous Solid Electrolyte for Long-Life All-Solid-State Lithium Metal Batteries.

The application of lithium metal anode in all-solid-state batteries has the potential to achieve both high energy density and safety performance. However, the presence of serious dendrite issues hinders this potential. Here, the ion transport pathways and orientation of dendrite growth are regulated by utilizing the differences of ionic conductivity in heterogeneous electrolytes. The in situ formed Li-Ge alloy phases from the spontaneous reaction between Li10GeP2S12 and the attracted dendrites greatly enhance the ability to resist dendrite growth. As an outcome, the heterogeneous electrolyte achieves a high critical current density of 2.1 mA cm-2 and long-term stable symmetrical battery operation (0.3 mA cm-2 for 17 000 h and 1.0 mA cm-2 for 2000 h). Besides, due to the superior interfacial stability and low interface impedance between the heterogeneous electrolyte and lithium anode, the Li||LiNi0.8Co0.1Mn0.1O2 full battery exhibits great cycling stability (80.5% after 500 cycles at 1.0 mA cm-2) and rate performance (125.4 mAh g at 2.0 mA cm-2). This work provides a unique strategy of interface regulation via heterogeneous electrolytes design, offering insights into the development of state-of the-art all-solid-state batteries.

Sabatier Relations in Electrocatalysts Based on High-entropy Alloys with Wide-distributed d-band Centers for Li-O2 Batteries.

Li-O2 battery (LOB) is a promising "beyond Li-ion" technology with ultrahigh theoretical energy density (3457 Wh kg-1 ), while currently impeded by the sluggish cathodic kinetics of the reversible gas-solid reaction between O2 and Li2 O2 . Despite many catalysts are developed for accelerating the conversion process, the lack of design guidance for achieving high performance makes catalysts exploring aleatory. The Sabatier principle is an acknowledged theory connecting the scaling relationship with heterogeneous catalytic activity, providing a tradeoff strategy for the topmost performance. Herein, a series of catalysts with wide-distributed d-band centers (i.e., wide range of adsorption strength) are elaborately constructed via high-entropy strategy, enabling an in-depth study of the Sabatier relations in electrocatalysts for LOBs. A volcano-type correlation of d-band center and catalytic activity emerges. Both theoretical and experimental results indicate that a moderate d-band center with appropriate adsorption strength propels the catalysts up to the top. As a demonstration of concept, the LOB using FeCoNiMnPtIr as catalyst provides an exceptional energy conversion efficiency of over 80 %, and works steadily for 2000 h with a high fixed specific capacity of 4000 mAh g-1 . This work certifies the applicability of Sabatier principle as a guidance for designing advanced heterogeneous catalysts assembled in LOBs.

Dual-ion conductors: from liquid to solid.

The traditional working principle within lithium-ion batteries relies on Li+ shuttling between the cathode and anode, namely the rocking-chair mechanism. A single working ion constrains the possibilities for battery design and the selection of electrode materials, while realizing multiple working ions offers the potential to break through the fundamental principles of traditional battery construction. Accordingly, it is necessary to develop dual-ion conductors to enable the migration of multiple working ions. This focus article starts by introducing traditional dual-ion batteries based on liquid electrolytes and their pros and cons. Then, solidifying liquid dual-ion conductors is expected to overcome these drawbacks, so the development of solid dual-ion conductors is discussed in detail. Specifically, basic design principles of solid dual-ion conductors are briefly proposed, including constructing continuous ion transport channels and choosing appropriately sized ion carriers. The potential applications of solid dual-ion conductors are also summarized, such as stabilizing the electrode/electrolyte interface and activating additional redox couples. The goal of this article is to inspire researchers in the development of dual-ion conductors and to contribute to the advancement of all-solid-state batteries.