Interface Re-Engineering of Li₁₀GeP₂S₁₂ Electrolyte and Lithium anode for All-Solid-State Lithium Batteries with Ultralong Cycle Life

Abstract

An ingenious interface re-engineering strategy was applied to in situ prepare a manipulated LiHPO protective layer on the surface of Li anode for circumventing the intrinsic chemical stability issues of LiGePS (LGPS) to Li metal, specifically the migration of mixed ionic-electronic reactants to the inner of LGPS, and the kinetically sluggish reactions in the interface. As consequence, the stability of LGPS with Li metal increased substantially and the cycling of symmetric Li/Li cell showed that the polarization voltage could keep relative stable for over 950 h at 0.1 mA cm within ±0.05 V. The optimized ASSLiB of LiCoO (LCO)/LGPS/Li with interface-engineered structure was able to deliver long cycle life and high capacity, i.e., a reversible discharge capacity of 131.1 mAh g at the initial cycle and 113.7 mAh g at the 500th cycle under 0.1 C with a retention of 86.7%. In addition, the factors effected on the interphases formation of the LGPS/Li interface were analyzed, and the mechanism of the stability between LGPS and Li anode with protective layer was further investigated. Moreover, the probable causes of battery degradation were also explored. Above all, this work would give an alternative strategy for the modification of Li anode in high energy density solid-state lithium metal batteries.

Advances and Prospects of Sulfide All‐Solid‐State Lithium Batteries via One‐to‐One Comparison with Conventional Liquid Lithium Ion Batteries

“…a,b) Reproduced with permission . Copyright 2018, Elsevier B.V. c–e) Reproduced with permission . Copyright 2017, American Chemical Society.…”

“…Furthermore, with regard to the interface engineering of lithium metal, Zhang et al developed an in situ LiH 2 PO 4 protective layer via the reaction between phosphoric acid and lithium metal anode (Figure c) . Interconnected protective layers uniformly covered the surface of the lithium metal anode with little voids (Figure d).…”

Solid‐State Lithium Batteries: Bipolar Design, Fabrication, and Electrochemistry

“…However, the following technical issues remain critical: uncontrollable growth of Li dendrites during cycling and high resistance at the interface between the SE and Li metal . Various approaches have been recently developed to engineer or stabilize the SE/Li interfaces . For instance, Zhou et al.…”

“…In the field of sulfide‐based SEs, Tatsumisago's group reported that thin In and Au layers formed on Li 2 S−P 2 S 5 SEs via vacuum evaporation undergo the alloying reaction with Li and hence enable the conformal contact between SEs and Li metal, resulting in facile Li + transport and enhanced rate performance . The protective layers such as Li 2 S−P 2 S 5 −P 2 O 5 and LiH 2 PO 4 were also found to inhibit the reduction reaction of LGPS SEs in contact with Li metal …”

Interfacial Incompatibility and Internal Stresses in All‐Solid‐State Lithium Ion Batteries

“…f) Interfacial impedance for the pristine and Ge-coated LAGP. Finally, lithium phosphates such as Li 3 PO 4 [213] and LiH 2 PO 4 [214] can also be sandwiched between the SSEs and Li to preclude their direct contact. An increased overpotential was clearly inspected after 50 h for the cell without Ge film, whereas the symmetrical cell with Ge film had a smaller overpotential and stabilized over 200 h. Reproduced with permission.…”