Designing a Quasi-Liquid Alloy Interface for Solid Na-Ion Battery

Abstract

Solid-state sodium-ion batteries are attracting great attention due to their high energy density and high safety. However, the Na dendrite growth and poor wettability between sodium and electrolytes seriously limit its application. Herein, we designed a stable and dendrite-suppressed quasi-liquid alloy interface (C@Na–K) for solid sodium-ion batteries (SSIBs). The batteries exhibit excellent electrochemical performance thanks to better wettability and accelerated charge transfer and nucleation mode shifts. The thickness of the liquid phase alloy interface fluctuates along with the exotherm of the cell cycling process, which leads to better rate performance. The symmetrical cell can cycle steadily over 3500 h at 0.1 mA/cm2 at room temperature, and the critical current density can reach 2.6 mA/cm2 at 40 °C. The full cells with the quasi-liquid alloy interface also show outstanding performance; the capacity retention can reach 97.1%, and the average Coulombic efficiency can reach 99.6% of the battery at 0.5 C even after 300 cycles. These results proved the feasibility of using a liquid alloy interface of the anode for high-energy SSIBs, and this innovative approach to stabilizing the interface performance could serve as a basis for the development of next-generation high-energy SSIBs.

Routes to high-performance layered oxide cathodes for sodium-ion batteries

“…18–27 However, although SIBs can be traced back to the same period as LIBs, the SIB industry has shown limited development compared to the prosperity of the LIB industry, especially since Sony first commercialized LIBs in the early 1990s when LIBs were widely used in various portable electronic devices and electric vehicles. 28–36 However, lithium resources are fairly expensive because of their scarcity on Earth and highly uneven global distribution. 37,38 Therefore, in recent years, SIBs have re-emerged and are being viewed as a favorable complement to LIBs, thus experiencing a renaissance.…”

Modulating the cathode interface in sodium-beta alumina-based semi-solid-state sodium cells using liquid-organic electrolytes

“…3 Modulation is necessary for all material classes and includes many methods, e.g., compositional tuning, 4 articial solid electrolyte interphases (SEI), 5 liquid interlayers, 6 carbon coating, 7 metal coating, [8][9][10] and alloying. 9,[11][12][13] It especially applies to the interface between the polycrystalline Na + conductor sodium-beta alumina solid electrolyte (BASE) and the negative electrode (NE, hereaer called the anode) 14,15 as well as to the positive electrode (PE, hereaer called cathode). 16 Several methods exist for modulating the BASEjPE interface, e.g., adding ionic liquids, [17][18][19] polymers, 20,21 or additional electrolytes.…”

Electrolyte Salts for Sodium-Ion Batteries: NaPF6 or NaClO4?

“…Sodium-ion batteries (SIBs) have become a research hotspot as promising next-generation rechargeable batteries, especially for low-speed electric vehicles and large-scale energy storage systems, owing to the natural abundance of sodium and a similar working principle to lithium-ion batteries. − Currently, cathode materials with commercial application prospects include layered oxides, Prussian blue analogs, and polyanion compounds, − and anode materials include soft and hard carbons. The electrolyte is indispensable in SIBs, as it undertakes the function of transmitting Na + between the cathode and anode and can form an electrode–electrolyte interphase (EEI) that inhibits parasitic reactions at the interface, thereby affecting the working voltage window and cycle performance. − …”