Building better solid‐state batteries with silicon‐based anodes

Abstract

Silicon (Si)‐based solid‐state batteries (Si‐SSBs) are attracting tremendous attention because of their high energy density and unprecedented safety, making them become promising candidates for next‐generation energy storage systems. Nevertheless, the commercialization of Si‐SSBs is significantly impeded by enormous challenges including large volume variation, severe interfacial problems, elusive fundamental mechanisms, and unsatisfied electrochemical performance. Besides, some unknown electrochemical processes in Si‐based anode, solid‐state electrolytes (SSEs), and Si‐based anode/SSE interfaces are still needed to be explored, while an in‐depth understanding of solid–solid interfacial chemistry is insufficient in Si‐SSBs. This review aims to summarize the current scientific and technological advances and insights into tackling challenges to promote the deployment of Si‐SSBs. First, the differences between various conventional liquid electrolyte‐dominated Si‐based lithium‐ion batteries (LIBs) with Si‐SSBs are discussed. Subsequently, the interfacial mechanical contact model, chemical reaction properties, and charge transfer kinetics (mechanical–chemical kinetics) between Si‐based anode and three different SSEs (inorganic (oxides) SSEs, organic–inorganic composite SSEs, and inorganic (sulfides) SSEs) are systemically reviewed, respectively. Moreover, the progress for promising inorganic (sulfides) SSE‐based Si‐SSBs on the aspects of electrode constitution, three‐dimensional structured electrodes, and external stack pressure is highlighted, respectively. Finally, future research directions and prospects in the development of Si‐SSBs are proposed.

High‐Safety Lithium‐Ion Batteries with Silicon‐Based Anodes Enabled by Electrolyte Design

“…By virtue of decent mechanical performance, nonflammability and zero leakage, solid-state electrolytes (SSEs) typically feature with high safety and hence are regarded as the ultimate solution for safety issues of batteries. [42][43][44][45][46][47] When paired with silicon anodes, the limited interfacial contact between SSEs and silicon-based anodes could get rid of the dilemma of continuous SEI growth, contributing to a stable interphase. [42,43] Besides, the expansion of silicon-based anodes may lead to intimate contact with SSEs, especially for polymer electrolytes and sulfide SSEs.…”

“…[42][43][44][45][46][47] When paired with silicon anodes, the limited interfacial contact between SSEs and silicon-based anodes could get rid of the dilemma of continuous SEI growth, contributing to a stable interphase. [42,43] Besides, the expansion of silicon-based anodes may lead to intimate contact with SSEs, especially for polymer electrolytes and sulfide SSEs. [42,43,47] Consequently, the combination of SSEs and silicon-based anodes shows promising prospects.…”

“…Additionally, solid state electrolytes (SSEs) provide non-flammability, zero leakage, and decent mechanical performance, offering convincing feasibility of enabling high safety. [42][43][44][45][46][47][48] It is worth mentioning that silicon anodes pairing with SSEs can generate a stable interface between them, retaining stable long-term cycling, and promising a bright future for silicon anodes. [47,49] Indeed, electrolyte design has been proved to effectively mitigate TR to some extent and is expected to play a bigger role in the future.…”

Manipulating charge-transfer kinetics and a flow-domain LiF-rich interphase to enable high-performance microsized silicon–silver–carbon composite anodes for solid-state batteries

“…Nevertheless, the practical adoption of Si anodes in LIBs is impeded by their rapid capacity decay caused by the huge volume variations (up to 300%) and subsequent solid-electrolyte-interphase (SEI) degradation during cycling. [4][5][6][7] In addition, the rate performance of Si anodes is still limited due to their low electrical and ionic conductivity. 8,9 To overcome these drawbacks, recent studies have been focused on numerous Si-based nanostructures, such as nanoparticles, 10,11 nanowires, 12 porous/hollow nanostructures, etc.…”

“…To address the volumetric expansion issues of the MSi anode, substantial attempts including binder optimization, 19 liquid electrolyte developments, 20 multilayer graphene cage coating, 21–23 covalent bonding strategy 24,25 and porous structure design 26 have been proposed to achieve enhanced electrochemical performance. To further avoid the side reaction between liquid electrolytes and the MSi anode, the interface passivation of sulfide-based solid-state electrolytes (SSEs) has been developed, 4,17 and therefore the continuous interfacial growth and irreversible lithium loss can be eliminated. Moreover, due to the limited contact between MSi and SSEs, the freshly formed surface of MSi anodes is not highly reactive to SSEs, which is favorable for the formation of a stable and passivating SEI.…”