Structure and ionic conductivity of a beta-alumina-based solid electrolyte prepared from sodium polyaluminate nanopowders

Lim

et al. 2015

Energy Environ. Sci.

223

156

Development of Na-ion battery electrolyte with high-performance electrochemical properties and high safety is still challenging to achieve. In this study, we report on a NASICON (Na 3 Zr 2 Si 2 PO 12 )-based composite hybrid solid electrolyte (HSE) designed for use in a high safety solid-state sodium battery for the first time. The composite HSE design yields the required solid-state electrolyte properties for this application, including high ionic conductivity, a wide electrochemical window, and high thermal stability.The solid-state batteries of half-cell type exhibit an initial discharge capacity of 330 and 131 mA h g À1 for a hard carbon anode and a NaFePO 4 cathode at a 0.2C-rate of room temperature, respectively.Moreover, a pouch-type flexible solid-state full-cell comprising hard carbon/HSE/NaFePO 4 exhibits a highly reversible electrochemical reaction, high specific capacity, and a good, stable cycle life with high flexibility. Broader contextThe considerable interest in Na-ion batteries has continued to increase as a result of their applicability to large-scale energy storage systems, and also because of the high abundance and uniform worldwide distribution of Na and its corresponding low cost compared to Li. However, safety issues related to the use of conventional combustible organic electrolytes in large-scale batteries for vehicle or grid applications are of great concern. It is anticipated that such safety issues can be fully addressed through the use of non-flammable solid electrolytes in solid-state batteries. However, the application of solid ceramic and polymer electrolytes in batteries has led to poor electrochemical performance, which is primarily due to the resultant high solid-solid interface resistance. Thus, a new electrolyte strategy is urgently required in order to overcome this problem. In this work, a NASICON (Na 3 Zr 2 Si 2 PO 12 ) ceramic-based hybrid solid electrolyte (HSE) is proposed and shown to exhibit high electrochemical performances as a result of its decreased interface resistance, high thermal stability, and high electrochemical stability. Using the HSE, a flexible pouch-type full cell of hard carbon/HSE/NaFePO 4 is assembled for the first time, exhibiting good and stable cycle performance with a high capacity. † Electronic supplementary information (ESI) available: XRD, FT-IR, SEM-EDX, DSC, FT-Raman, Arrhenius plots, bond length of CF 3 SO 3 , shrinkage test, chargedischarge curves, photographs of a flexible solid-state Na battery, short-term cycling of flexible solid-state batteries with conducting and non-conducting ceramic. See

Section: Introductionmentioning

confidence: 99%

A hybrid solid electrolyte for flexible solid-state sodium batteries

Lim

et al. 2015

Energy Environ. Sci.

223

156

“…This development was crucial as it led to the assembly of solid-state batteries (Ag/Ag3SI/I2), effectively addressing the flammability issues associated with organic liquid electrolytes [9][10][11] . Further advancements were made in 1967 with the Na2O•11Al2O3 electrolyte (beta-alumina), recognized for its high Na + ionic conductivity (10 3 S cm -1 at 300 ºC) and its application in Na-S batteries [12][13] .…”

Section: Introductionmentioning

confidence: 99%

Correlation between mechanical properties and ionic conductivity of sodium superionic conductors: a relative density-dependent relationship

Cheng,

Yang,

Liu

et al. 2024

Preprint

Sodium superionic conductors (NASICON) are pivotal for the functionality and safety of solid-state sodium batteries. Their mechanical properties and ionic conductivity are key performance metrics, yet their interrelation remains inadequately understood. Addressing this gap is vital for concurrent enhancements in both properties. This study summarizes recent literature on NASICON solid electrolytes Na1+xZr2SixP3-xO12 (NZSP, 0≤x≤3), highlighting the mechanical properties and ionic conductivity, and identifies a positive correlation between mechanical strength, in particular hardness, and ionic conductivity at ambient temperatures. Microstructural analysis reveals that a range of factors, including relative density, grain size, secondary phases, and crystallographic structures, significantly influence material properties. Notably, an increase in relative density uniquely contributes to simultaneous enhancements in both ionic conductivity and mechanical strength. Consequently, future research should prioritize enhancing the relative density of NASICON solid electrolytes, possibly employing advanced techniques, including sol-gel process, spark plasma sintering (SPS), and microwave-assisted sintering. The correlation between mechanical properties and ionic conductivity observed in NASICON solid electrolytes extends to other high-temperature sintered oxide electrolytes like Li7La3Zr2O12 (LLZO). This investigation not only suggests a potential linkage between these crucial properties but also guides subsequent strategies for refining solid electrolytes for advanced battery technologies.

“…This development was crucial as it led to the assembly of a solid-state cell Ag/Ag3SI/I2, effectively addressing the flammability issue associated with organic liquid electrolytes [15][16][17][18]. Further advancements were made in 1967 with the β-alumina electrolyte (Na2O•11Al2O3), recognized for its high Na + conductivity (10 6 mS/cm at 300 ºC) and its application in Na-S batteries [19,20]. A pivotal breakthrough occurred in 1976 when Hong and Goodenough synthesized a promising Na + inorganic SE, Na1+xZr2SixP3-xO12 (NZSP, 0≤x≤3) [21].…”

Section: Introductionmentioning

confidence: 99%

Correlation between mechanical properties and ionic conductivity of sodium superionic conductors: a relative density-dominant relationship

Cheng,

Yang,

Liu

et al. 2024

Preprint

Sodium superionic conductors (NASICON) are pivotal for the functionality and safety of solid-state sodium batteries. Their mechanical properties and ionic conductivity are key performance metrics, yet their correlation remains inadequately understood. Addressing this gap is vital for concurrent enhancements in both properties. This study summarizes recent literature on the sintered polycrystalline NASICON solid electrolyte Na1+xZr2SixP3-xO12 (NZSP, 0≤x≤3), focusing on its mechanical properties and ionic conductivity, and identifies a positive correlation between these properties at ambient temperatures. Microstructural analysis reveals that a range of factors, including relative density, grain size, secondary phases, and crystal structures, significantly influence the properties of NZSP. Notably, an increase in relative density uniquely contributes to simultaneous enhancements in both hardness and ionic conductivity. Consequently, future research should prioritize enhancing the relative density of NZSP, potentially by employing advanced sintering techniques such as spark plasma sintering (SPS) and microwave-assisted sintering. The correlation between mechanical properties and ionic conductivity observed in NZSP is also evident in other oxide solid electrolytes, such as garnet Li7La3Zr2O12 (LLZO). This investigation not only suggests a potential linkage between these crucial properties but also guides subsequent strategies for refining polycrystalline oxide solid electrolytes for advanced battery technologies.