Wide‐Temperature, Long‐Cycling, and High‐Loading Pyrite All‐Solid‐State Batteries Enabled by Argyrodite Thioarsenate Superionic Conductor

Abstract

Rechargeable FeS2 battery has been regarded as a promising energy storage device, due to its potentially high energy density and ultralow cost. However, the short lifespan associated with the shuttle effect of polysulfides, large volume change, agglomeration of Fe0 nanoparticles, narrow operating temperature range, and sluggish reaction kinetics, greatly impede the application of rechargeable FeS2 lithium‐ion batteries. Herein, an all‐solid‐state battery (ASSB) coupling commercialized FeS2 is proposed with a novel superionic conductor Li6.8Si0.8As0.2S5I (LASI‐80Si) to overcome these challenges. The shuttle effect of polysulfides and volume change of FeS2 are suppressed or completely eliminated in ASSB, due to solid‐solid conversion of Li2S/S and large stacking pressure, respectively. Furthermore, the operating temperature range (−60–60 °C) is significantly expanded by the ultra‐high and temperature‐insensitive ionic conductivity of LASI‐80Si (Ea = 0.20 eV), along with the superior FeS2/LASI‐80Si interface stability. Thanks to the extra Li+ provided by Li2S and LiI functional phases, the “bridge” effect of LiI on facile interfacial Li‐ion conduction, and the enhanced reaction kinetics of LASI‐80Si (σLi+=${\sigma _{L{i^ + }}} = $ 10.4 mS cm−1), ASSBs with LASI‐80Si deliver long cycle life (244 cycles at 0.1 C and 600 cycles at 1 C), superior rate capability (20 C), high areal mass loading (13.37 mg cm−2), and ultrahigh areal capacity (9.05 mAh cm−2). These inspiring results demonstrate the enormous potential of LASI‐80Si and FeS2 combination for practical application of wide‐temperature and large‐capacity ASSBs.

High-areal-capacity and long-cycle-life all-solid-state battery enabled by freeze drying technology

“…With the proposal of clean energy storage strategy and the rapid development of electric vehicles, traditional liquid lithium ion batteries present potential safety hazards because of their flammable liquid electrolytes, 1,2 while all-solid-state batteries (ASSBs) using solid electrolytes (SEs) have attracted great research attention because of their unique non-flammability and high safety. [3][4][5][6][7][8][9][10] In addition, the introduction of SEs makes the application of lithium metal anode possible, 11 which greatly increases the energy density of a battery to meet the growing demand for energy storage systems. [12][13][14] Among different types of SEs, oxide SEs have good chemical stability and wide electrochemical window, but stiffness and brittleness make their application in ASSBs very challenging, and superhigh sintering temperature is usually required for good interfacial contact.…”

Interface Engineering of All‐Solid‐State Batteries Based on Inorganic Solid Electrolytes

“…Doping with Si or Cl yields a series of sulfide electrolytes with high ionic conductivity, such as Li 10.35 Si 1.35 P 1.65 S 12 (2 × 10 À 2 S cm À 1 ), [32] Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 (2.5 × 10 À 2 S cm À 1 ) [25] and Li 6.8 Si 0.8 As 0.2 S 5 I (1.04 × 10 À 2 S cm À 1 ). [33] Substituting Sn, As and Sb yields a series of sulfide electrolytes with appropriate ionic conductivity and high air stability, such as Li 10 Ge(P 0.925 Sb 0.075 ) 2 S 12 (1.75 × 10 À 2 S cm À 1 ), [34] Li 3.875 Sn 0.875 As 0.125 S 4 (2.45 × 10 À 3 S cm À 1 ) [35] and Li 6.2 P 5.8 Sn 0.2 S 5 I (3.5 × 10 À 4 S cm À 1 ). [36] Compared with oxide SEs, sulfide SEs process higher conductivities, lower grain boundary resistance and better formability and these are why sulfide SEs can be cold-pressed to obtain higher ionic conductivity.…”

“…Based on sulfide electrolytes with high ionic conductivity, there are two research directions of electrolyte modification, one is to further improve ionic conductivity, the other is to improve stability. Doping with Si or Cl yields a series of sulfide electrolytes with high ionic conductivity, such as Li 10.35 Si 1.35 P 1.65 S 12 (2×10 −2 S cm −1 ), [32] Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 (2.5×10 −2 S cm −1 ) [25] and Li 6.8 Si 0.8 As 0.2 S 5 I (1.04×10 −2 S cm −1 ) [33] . Substituting Sn, As and Sb yields a series of sulfide electrolytes with appropriate ionic conductivity and high air stability, such as Li 10 Ge(P 0.925 Sb 0.075 ) 2 S 12 (1.75×10 −2 S cm −1 ), [34] Li 3.875 Sn 0.875 As 0.125 S 4 (2.45×10 −3 S cm −1 ) [35] and Li 6.2 P 5.8 Sn 0.2 S 5 I (3.5×10 −4 S cm −1 ) [36] …”

Anode Interfacial Issues in Solid‐State Li Batteries: Mechanistic Understanding and Mitigating Strategies

“…ASSLBs using SEs are envisaged to surpass current Li-ion batteries in terms of safety, energy density, and cycling life. [9][10][11][12][13][14] However, the application of ASSLB is still restricted by problems including electrode/SE interfacial stability, [15][16][17][18][19] chemical/air stability of SEs [20][21][22][23] and thermal stabilities of SEs and electrode/SE interfaces. [24][25][26][27][28][29] Among them, Li metal/SE interfacial issues such as Li dendrite formation, interfacial electrochemical reactions, and chemo-mechanical degradation significantly limit the safety, power density, and cycling stability of ASSLBs.…”