Growth of lithium-indium dendrites in all-solid-state lithium-based batteries with sulfide electrolytes

Abstract

All-solid-state lithium-based batteries with inorganic solid electrolytes are considered a viable option for electrochemical energy storage applications. However, the application of lithium metal is hindered by issues associated with the growth of mossy and dendritic Li morphologies upon prolonged cell cycling and undesired reactions at the electrode/solid electrolyte interface. In this context, alloy materials such as lithium-indium (Li-In) alloys are widely used at the laboratory scale because of their (electro)chemical stability, although no in-depth investigations on their morphological stability have been reported yet. In this work, we report the growth of Li-In dendritic structures when the alloy material is used in combination with a Li6PS5Cl solid electrolyte and Li(Ni0.6Co0.2Mn0.2)O2 positive electrode active material and cycled at high currents (e.g., 3.8 mA cm−2) and high cathode loading (e.g., 4 mAh cm−2). Via ex situ measurements and simulations, we demonstrate that the irregular growth of Li-In dendrites leads to cell short circuits after room-temperature long-term cycling. Furthermore, the difference between Li and Li-In dendrites is investigated and discussed to demonstrate the distinct type of dendrite morphology.

Prospects of halide-based all-solid-state batteries: From material design to practical application

“…Besides, some organic solid polymer electrolytes and inorganic-polymer composites that are compatible with Li metal and halide SSEs are also worth developing for halide ASSBs ( 4 , 95 , 96 ). Besides Li metal, other anode materials, such as silicon ( 97 ), silicon-carbon composites ( 98 ), and Li 4 Ti 5 O 12 ( 10 ) and alloy anodes ( 99 – 101 ), are also worth investigating in halide ASSBs considering their high thermal stability and low-cost fast-charging capability. Using halide SSEs to develop anode-free ASSBs will also be an emerging direction for realizing ultrahigh energy density ( 2 ).…”

On the Relative Importance of Li Bulk Diffusivity and Interface Morphology in Determining the Stripped Capacity of Metallic Anodes in Solid-State Batteries

“…On the other hand, it has been reported that the use of lithium alloys can help to form a more stable interface with the solid electrolyte, and various lithium alloys have been used as anodes ,− or as interlayers between lithium metal and solid electrolyte. − The improved morphological stability of the interface has often been attributed to a fast lithium diffusivity in lithium alloys. ,,, During stripping, vacancies formed at the interface would quickly be refilled, while during plating the fast lithium diffusion into the bulk of the anode alloy would maintain the activity of lithium at the interface below one and limit the accumulation of lithium atoms at the interface. A number of alloys have been reported to have lithium diffusivities significantly exceeding lithium self-diffusivity, with chemical diffusion coefficients between 10 –8 and 10 –6 cm 2 ·s –1 at room temperature measured by galvanostatic or potentiostatic electrochemical titration techniques in liquid electrolytes. ,− Among these lithium alloys, the Li-Mg system has attracted particular interest. ,, Mg has an exceptionally wide solubility range in Li, with the β-phase region spanning from 0 to 70 at.% Mg (see Figure a), so that there may be no phase transformation during electrochemical cycling of Li-Mg giving better microstructural stability .…”

Regulation of the Interfaces Between Argyrodite Solid Electrolytes and Lithium Metal Anode

“…In addition to the widespread use of silver and lithium to form lithium-silver alloys to regulate the growth of lithium dendrites, other alloying elements also have their advantages in regulating lithium dendrites. Zhang et al (Luo et al, 2021) took advantage of the inherent good deformability of the Li-In alloy to assemble the cell under high pressure to make a tighter fit between the electrolyte and the negative electrode of the alloy (Figure 1H). The close contact between the electrolyte and the anode eliminates the voids at the interface and suppresses the generation of lithium dendrites.…”