A Solid Electrolyte Based on Electrochemical Active Li₄Ti₅O₁₂ with PVDF for Solid State Lithium Metal Battery

Abstract

density and larger battery pack, difficulty of battery management accompanied with safety issues also emerges, drawing great concerns of public to solid state batteries (SSBs). [2] By replacing the ignitable organic liquid electrolytes (LE) with solid state electrolytes (SSEs), flammability of devices is supposed to be largely eliminated. [3,4] Besides, bipolar-stacked design with lithium anode realized by SSEs with a high mechanical strength could further burst the energy density of SSBs. [5] However, prior to implementation of solid-state batteries, inadequate properties and complicated manufacture process of SSEs remain issues to overcome. [6] Other than ionic conductivity that inferior to liquid electrolytes, performances of SSEs are greatly restricted by undesirable electrode/electrolyte interfacial nature, in either chemistry or physics. [7] Numerous researchers have discussed poor stability of oxide-type SSEs against lithium metal anode. [8,9] Transition element containing SSEs like Li 3x La (2/3−x) TiO 3 (LLTO) [10] and Li 1+x Al x Ge 2−x (PO 4 ) 3 (LAGP) [11] could undergo a fast and constant reduction to form an inserting interphase consisting of ionic/electronic mixed conductive species, followed with short circuit or physical deform of SSEs causing cell failure. [12] Garnet-type Li 7 La 3 Zr 2 O 12 (LLZO) was found electrochemically stable against lithium metal, but suffers from contact losing with anode because its rigidity and lithiophobic surface. [13] Sulfide-based SSEs like thiophosphates (Li 2 S-P 2 S 5 ) mostly suffers from undesired performance at cathode side caused by chemical deterioration and the space charge effect. [14] As incompetent nature of SSE materials themselves, many efforts were made to build an ideal system with heterogeneous interface. Surface treatments by vapor deposition, magnetron sputtering, [15] chemical soaking [16] or physical coating [17] were conducted to form an artificial layer on SSEs. The interphase that consist of Al, [18] Ge, [19] liquid alloy, [20,21] graphite, [22] ZnO [23] or C 3 N 4 [24] could change the surface to lithiophilic and thus improve Li|SSE contact. The compounds including ionic liquids, [25] conductive polymers [26] and salts like LiF, [27] exhibiting thermodynamic stability against the electrodes, were considered ideal interphase to inhibit electrochemical decomposition of SSEs. Element doping coupled with hierarchy design also achieved visible enhancements with less side effect on ion transport. [28,29] In parallel with researches unveiling the nature and mechanism in solid state battery, numbers of investigations have been pursuing methods to stabilize their performance as well as to reduce the cost. Simple preparation and earth-abundant ingredients are preconditions for a solid state electrolyte to be suitable for scalable production. In this work, a commercial anode active material, spinel Li 4 Ti 5 O 12 , is introduced for the first time, which has high ionic conductivity to sustain high rate charge/discharge with considerable high perform...

Supramolecular Polymer Ion Conductor with Weakened Li Ion Solvation Enables Room Temperature All‐Solid‐State Lithium Metal Batteries

“…In addition, although the PEO-LiTFSI-based cell possesses a similar bulk resistance compared to the SPC-based cell at 60 °C (Figure 5b), the cycling stability of the latter is much higher (Figure 5d), which can be attributed to the lower concentration polarization caused by its decreased interfacial resistance. [45] In view of these results, the crucial role of interfacial resistance for implementing steady lithium plating/stripping at around room temperature is corroborated, therefore, the "weak solvation" structure of Li + in the SPC realizes low resistance at lithium/electrolyte interface and reinforced mechanical properties, which is not commonly observed in polymer electrolytes. This allows for stable operation of ASSLMBs within wide temperature range, especially around room temperature.…”

Architectural design and electrochemical performance of MOF‐based solid‐state electrolytes for high‐performance secondary batteries

“…The MOF‐based SSEs not only inherit the characteristics of MOFs, including regular channels, high porosity, good stability, and active open sites, but also exhibit good flexibility and interface contact. [ 59–63 ]…”

“…regular channels, high porosity, good stability, and active open sites, but also exhibit good flexibility and interface contact. [59][60][61][62][63] Research has proved that the interaction or the binding between polymer matrixes and MOFs plays an important role in the enhancement of the performance for the MOF-incorporate polymer composites SSEs. In the porous structures, the monomers with small size are introduced first, and then the polymerization occurs in the channels.…”

A Separator with Double Coatings of Li4Ti5O12and Conductive Carbon for Li‐S Battery of Good Electrochemical Performance

“…LTO has the advantages of low cost and good stability as commercial anode material for lithium ion batteries. [32][33][34][35] Furthermore, it can improve the Li + transport ability. It can also form a stable additional layer on the separators to barrier the transport of polysulfides, which improves the utilization of active sulfur and accelerates the redox kinetics of S electrode.…”