Recent Configurational Advances for Solid-State Lithium Batteries Featuring Conversion-Type Cathodes

Abstract

Solid-state lithium metal batteries offer superior energy density, longer lifespan, and enhanced safety compared to traditional liquid-electrolyte batteries. Their development has the potential to revolutionize battery technology, including the creation of electric vehicles with extended ranges and smaller more efficient portable devices. The employment of metallic lithium as the negative electrode allows the use of Li-free positive electrode materials, expanding the range of cathode choices and increasing the diversity of solid-state battery design options. In this review, we present recent developments in the configuration of solid-state lithium batteries with conversion-type cathodes, which cannot be paired with conventional graphite or advanced silicon anodes due to the lack of active lithium. Recent advancements in electrode and cell configuration have resulted in significant improvements in solid-state batteries with chalcogen, chalcogenide, and halide cathodes, including improved energy density, better rate capability, longer cycle life, and other notable benefits. To fully leverage the benefits of lithium metal anodes in solid-state batteries, high-capacity conversion-type cathodes are necessary. While challenges remain in optimizing the interface between solid-state electrolytes and conversion-type cathodes, this area of research presents significant opportunities for the development of improved battery systems and will require continued efforts to overcome these challenges.

Keywords: Li–S battery; all-solid-state battery; chalcogen cathode; chalcogenide cathode; fluoride cathode; halide cathode; metallic lithium anode; solid-state electrolyte; sulfide cathode; sulfur cathode.

Figure 1

Schematic drawing of the lithiation reaction of conversion-type cathodes.

Figure 2

Schematic illustration of the advantages of using conversion-type cathodes in lithium solid-state batteries.

Figure 3

The charge/discharge voltage curves of a Li–S battery with (a) an ether-based liquid electrolyte and (b) a carbonate-based liquid electrolyte or a solid-state electrolyte. Reproduced with permission from ref. [61]. Copyright 2020, Royal Society of Chemistry (London, UK). (c) Schematic drawing of an all-solid-state lithium-sulfur battery with a well-mixed sulfur cathode. Reproduced with permission from ref. [66]. Copyright 2017, Wiley-VCH (Weinheim, Germany). (d) Schematic drawing of a cathode-supported and Kevlar fiber-reinforced all-solid-state Li−Li₂S cell. Reproduced with permission from ref. [67]. Copyright 2019, ACS Publications (Washington, DC, USA). (e) Schematic drawing of an all-solid-state Li–S battery with a hybrid LLZO/PEO electrolyte system. Reproduced with permission from ref. [68]. Copyright 2017, ACS Publications (Washington, DC, USA). (f) Schematic drawing of a hybrid Li||LYZP||Li₂S₆ cell with the liquid electrolyte on both sides of the LYZP membrane. Reproduced with permission from ref. [78]. Copyright 2016, Wiley-VCH (Weinheim, Germany).

Figure 4

(a) Schematic drawing of an all-solid-state Li–Se battery. Reproduced with permission from ref. [87]. Copyright 2018, Royal Society of Chemistry (London, UK). (b) Cell configuration of the molten Li–Se cell tested at 465 °C. Reproduced with permission from ref. [88]. Copyright 2021, ACS Publications (Washington, DC, USA). (c) Schematic drawing of a Li–SeS_x solid-state battery. Reproduced with permission from ref. [61]. Copyright 2020, Royal Society of Chemistry (London, UK). (d) Schematic drawing of an Li-In||LPSCB||LPSCB-MWCNTs cell with a monolithic structure. (e) Schematic drawing of the LPSCB-MWCNTs composite cathode. Reproduced with permission from ref. [90]. Copyright 2021, Wiley-VCH (Weinheim, Germany).

Figure 5

Schematic drawing of an all-solid-state lithium battery (a) without cathode-doped electrolyte and (b) with cathode-doped electrolyte. Reproduced with permission from ref. [100]. Copyright 2020, Elsevier (Amsterdam, The Netherlands). (c) Schematic drawing of the redox reactions of FeS₂ and Co_0.1Fe_0.9S₂ cathodes. Reproduced with permission from ref. [101]. Copyright 2019, ACS Publications (Washington, DC, USA). (d) Schematic drawing of the solid-state hybrid Li–S/VS₂/LPS battery. Reproduced with permission from ref. [108]. Copyright 2021, Wiley-VCH (Weinheim, Germany). (e) Schematic drawing of the solid-state hybrid Li–TiS₂/LPS battery. Reproduced with permission from ref. [109]. Copyright 2014, Springer (Berlin/Heidelberg, Germany).

Figure 6

(a) Schematic drawing of the crystallographic reaction mechanism that occurs during the discharge of metal fluoride electrodes. Reproduced with permission from ref. [116]. Copyright 2007, Elsevier (Amsterdam, The Netherlands). (b) Schematic drawing of interface environment of Li/IL-LATP (left) and Li/IL@SP-LATP (right) during cycling process. Reproduced with permission from ref. [128]. Copyright 2022, Elsevier (Amsterdam, The Netherlands).

Figure 7

The failure mechanisms of conversion-type cathodes in a liquid electrolyte: (a) lithium dendrite formation on the anode, (b) cathode active material dissolution, and (c) fractured cathode electrolyte interface. (d) Schematic drawing of possible interfacial conditions in the cathode region of a solid-state lithium battery with a conversion-type cathode.