Bendable and Thin Sulfide Solid Electrolyte Film: A New Electrolyte Opportunity for Free-Standing and Stackable High-Energy All-Solid-State Lithium-Ion Batteries

Abstract

Bulk-type all-solid-state lithium batteries (ASLBs) are considered a promising candidate to outperform the conventional lithium-ion batteries. Unfortunately, the current technology level of ASLBs is in a stage of infancy in terms of cell-based (not electrode-material-based) energy densities and scalable fabrication. Here, we report on the first ever bendable and thin sulfide solid electrolyte films reinforced with a mechanically compliant poly(paraphenylene terephthalamide) nonwoven (NW) scaffold, which enables the fabrication of free-standing and stackable ASLBs with high energy density and high rate capabilities. The ASLB, using a thin (∼70 μm) NW-reinforced SE film, exhibits a 3-fold increase of the cell-energy-density compared to that of a conventional cell without the NW scaffold.

Binder-free sheet-type all-solid-state batteries with enhanced rate capabilities and high energy densities

“…The removal of PPC even from large-area SE sheets with high PPC content induces no adverse effects on the conductivity of the SE, implying the possibility of preparing large-area sheet-type cells which are important for applications. The binder-free sheet-type full-cells were also free-standing, similar to the previously reported binder 12,15 , polymer mesh 12 and nonwoven 13 -containing sheet-type cells. This property was accomplished by the intimate contact between the SE and the active materials through the plastic deformation of SE 19,20 by compression after heat-treatment.…”

“…These batteries exhibited an energy density of 115 Wh kg −1 , which is a ~2.6–5-fold increase compared with conventional pellet-type cells (LiCoO 2 /graphite) 10,11 and a 2.6-fold increase relative to nonwoven-containing sheet-type cells (LiCoO 2 /Li 4 Ti 5 O 12 ) 13 . This feat was accomplished through the fabrication of thinner SE sheets and homogeneously dispersed electrodes with higher active material weight fractions by using PPC.…”

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

“…The impregnation of SEs into porous scaffolds would provide the design flexibility of the composite electrodes for SSLBs, as demonstrated using Li 3 PS 4 and LGPS. [149] Similarly, a PE-supported SE membrane was proposed by Chen et al: an SE was directly casted onto the electrode to enhance the wetting properties and to reinforce the interfacial adhesion. [150] Li metal is considered to be an ultimate anode material for SSLBs with high energy density.…”

“…[46,165] Ni has been used as BPs for the Li NE and TiS 2 PE, [46] and more recently, Nam et al demonstrated the chemical stability of Ni with a Li 3 PS 4 SE and constructed a free-standing, stackable, bipolar SSLB using a Ni-coated non-woven scaffold BP. [149] Stainless steels (referred to as SUS) are Fe-based alloys and are widely used for the components of coin-type cells. They have a high contact resistance but high chemical stability, due to the presence of passivation layers on their surfaces.…”

“…Although the non-fluidic properties of SEs enable a bipolar design by preventing the flow of ions between adjacent cells, the stacking of multiple cells within a single package has been found to be very challenging, and only a few reports on bipolar SSLBs, mostly proof-of-concept studies, have been published thus far. [37,38,149,163,166,170,[173][174][175][176][177][178] The stacking strategies for bipolar SSLBs reported in the literature may be broadly classified into (i) the lamination of free-standing SE sheets and (ii) the printing of SE slurries. The former involves the sequential lamination of free-standing SE sheets and electrode-coated BPs, both of which have sufficient mechanical stability.…”