Cross-linked beta alumina nanowires with compact gel polymer electrolyte coating for ultra-stable sodium metal battery

Abstract

Sodium metal batteries have potentially high energy densities, but severe sodium-dendrite growth and side reactions prevent their practical applications, especially at high temperatures. Herein, we design an inorganic ionic conductor/gel polymer electrolyte composite, where uniformly cross-linked beta alumina nanowires are compactly coated by a poly(vinylidene fluoride-co-hexafluoropropylene)-based gel polymer electrolyte through their strong molecular interactions. These beta alumina nanowires combined with the gel polymer layer create dense and homogeneous solid-liquid hybrid sodium-ion transportation channels through and along the nanowires, which promote uniform sodium deposition and formation of a stable and flat solid electrolyte interface on the sodium metal anode. Side reactions between the sodium metal and liquid electrolyte, as well as sodium dendrite formation, are successfully suppressed, especially at 60 °C. The sodium vanadium phosphate/sodium full cells with composite electrolyte exhibit 95.3% and 78.8% capacity retention after 1000 cycles at 1 C at 25 °C and 60 °C, respectively.

A high-volumetric-capacity bismuth nanosheet/graphene electrode for potassium ion batteries

“…Compared with the conventional highly porous nanostructured Bibased electrodes for PIBs, the higher ICE of the BiNS/ rGO-30 electrode resulted from the formation of less SEI on the relatively dense membrane electrode [21,24,36]. Compared with the pure BiNS electrode, the higher ICE of the BiNS/rGO-30 electrode resulted from its excellent structural stability that can avoid the destruction of SEI during cycling [37]. Due to a certain amount of potassium ions are sacrificed in the SEI formation process, the second discharge capacity of the BiNS/rGO-30 electrode is decreased to 342.5 mA h g −1 , which is lower than the initial discharge capacity.…”

The critical role of inorganic nanofillers in solid polymer composite electrolyte for Li+ transportation

“…[7][8][9] However, substantial advances of LIBs have encountered the performance bottleneck in recent years. [10][11][12][13] In the current situation, the limited practical energy density (100-220 Wh•kg −1 ) is the major issue besetting their further development in commercialization, which hardly satisfies the ever-increasing demand from advanced electrical applications and technologies. 14 Hence, new lithium-based batteries with higher energy density and larger power density are urgently needed.…”

Toward High Energy Density All Solid‐State Sodium Batteries with Excellent Flexibility

“…Many efforts have been made to exploit various solid‐state electrolytes that include solid polymer electrolytes (SPEs) and inorganic ceramic electrolytes (ICEs) . The ICEs (i.e., garnet, NASICON, perovskite, and sulfides‐type materials) usually exhibit considerable ionic conductivity (>10 −4 S cm −1 at RT), good thermal stability and robust mechanical strength . However, the intrinsic high roughness and rigidity of ICEs will cause poor contact with electrode materials and difficulties in the processing, leading to high contact resistance and manufacturing cost .…”