Alkali-Metal Anodes: From Lab to Market

Abstract

Alkali-metal batteries (AMBs) are one of the most promising candidates for next-generation high-energy battery systems. However, dendrite growth and serious safety implications limit the commercialization of AMBs. After years of development, the process of bringing alkali-metal anodes from lab to market is still full of tremendous challenges in terms of safety and cycle life. In this review, we divide the commercialization process of alkali-metal anodes into three stages: the first stage is fundamental researches on alkali-metal anodes, the second stage is the application of alkali-metal anodes in high-energy-density battery systems, and the third stage is satisfying the needs of industrialization. We mainly focus on the second and third stages and attempt to establish a relationship between academia and industry in this field. Finally, we give several perspectives on opportunities and challenges in the future development of AMBs for practical applications.

Sodiophilically Graded Gold Coating on Carbon Skeletons for Highly Stable Sodium Metal Anodes

“…High-energy electrochemical energy storage devices are attracting increasing attention owing to the ever-growing demand in portable electronics, electric cars, and grid storage systems. [1][2][3][4][5] Sodium (Na) metal is recognized as an attractive anode material for Na batteries because of its high theoretical specific capacity of 1166 mAh g −1 and low electrochemical potential of −2.714 V versus the standard hydrogen electrode. [4,6,7] However, Na-metal batteries (NMBs) have several challenges due to the presence of metallic Na, including, 1) the nonuniform deposition of Na which leads to the uncontrollable growth of Na dendrite, eventually short-circuiting the batteries, 2) the large volume changes occurring during plating/stripping cycles because of its hostless nature, and 3) the formation of unstable solid electrolyte interphase (SEI) layers at the expense of continuous depletion of the electrolyte.…”

“…[4,6,7] However, Na-metal batteries (NMBs) have several challenges due to the presence of metallic Na, including, 1) the nonuniform deposition of Na which leads to the uncontrollable growth of Na dendrite, eventually short-circuiting the batteries, 2) the large volume changes occurring during plating/stripping cycles because of its hostless nature, and 3) the formation of unstable solid electrolyte interphase (SEI) layers at the expense of continuous depletion of the electrolyte. [3,7,8] In fact, all these issues are interrelated and lower the coulombic efficiency (CE), trigger serious safety hazards, and are ultimately responsible for the short lifespan of NMBs. [7,9,10] Many efforts have been directed to circumventing these challenges, including the optimization of electrolyte composition, [11][12][13] the construction of artificial SEI layers, [14][15][16] the modulation of morphology/structure of current collectors and hosts, [17][18][19][20][21][22][23][24] the building of interlayers, [10,25] and the use of solidstate electrolytes.…”

High Performance Voltage Tailorable Room-temperature Ca-metal Batteries

“…Since the ionic radius of lithium (~0.76 Å) is smaller than that of calcium (~1.00 Å), it's reasonable to conclude that Ca insertion was accompanied by the insertion of Li, although we could't present the variation of Li element limited by the characterization technique. 1,7,28 Relating the cathodic peaks mentioned above with the analysis in XRD and EDX results, we can readily concluded that the cathodic peaks at 3.08 and 3.88 V was resulted from extraction reaction of absorded in surface or intercalated in graphitic layers, while the peaks at 1.73, 0.6, 0.32, and 0.03 V were attribtued to adsorption or intercalation reaction from Li + and Ca 2+ respectively. Moreover, the relay insertion/extraction of cations and anions consisting of adsorption-desorption and intercalation/deintercalation chemistry processes were also demonstrated in the ex situ HAADF-STEM, element mapping, and HRTEM images (Figure 4).…”

Stable Interface between Lithium and Electrolyte Facilitated by a Nanocomposite Protective Layer

“…Due to its high theoretical capacity (3860 mAh g −1 ) as well as low redox potential (−3.04 V vs standard hydrogen electrode), lithium (Li) metal is considered the ideal anode material for the next‐generation battery . However, the practical use of Li metal anode in organic liquid electrolyte is hindered by several issues such as low coulombic efficiency and unstable solid‐electrolyte interface (SEI) . Moreover, safety issues related to the high flammability of organic liquid electrolyte and dendritic Li formation are also serious concerns when Li metal‐based batteries are applied in electric vehicles …”

“…It has been widely reported that metal fluorides (e.g., LiF) play a crucial role in forming a stable SEI layer . In this work, a facile and rapid coating strategy is proposed to quickly form a nanocomposite protecting layer consisting of MgF 2 , LiF, and B 2 O 3 on Li metal.…”