Fundamental Mechanisms and Promising Strategies for the Industrial Application of SiO_x Anode

Abstract

SiOx anode with higher specific capacity than graphite and better capacity retention than pure Si has received great attention from both academia and the industry. However, the further application of SiOx suffers from its low initial Coulombic efficiency and inadequate capacity retention. The academia has reported numerous strategies to overcome these obstacles, such as nanosizing, pore designing, nanoarchitecture, etc., while seldom did they satisfy the requirement of the industry, which asks for anode material with excellent performance in all performance metrics (e.g., specific capacity, initial Coulombic efficiency, capacity retention, tap density). Besides, the reproducibility, production cost, and safety of the strategies are less concerned, leading to the “misalignment” between academia and the industry. In this review, the advancements in the modification strategies, which are already or likely to be accepted by the industry, are introduced in detail and critically evaluated. Moreover, the fundamental mechanisms of SiOx and the relationship between its structure and performance are systematically discussed. In the end, outlooks and suggestions for future research are given to provide meaningful guidance.

Rational design of SiOx based anode materials for next generation lithium-ion batteries

“…In order to realize the potential of SiO x /C composites as anode materials with excellent electrochemical performance, it is essential to carefully design the SiO x precursors. 39 The size and morphology of the SiO x core can significantly impact the electrochemical performance of the composites. It is essential for a valuable process to not only prioritize cost considerations but also place significant emphasis on environmental friendliness.…”

Amorphous SiO2 Nanoparticles Encapsulating a SiO Anode with Strong Structure for High-Rate Lithium-Ion Batteries

“…There has been a significant surge in demand for lithium-ion batteries (LIBs) in the market, primarily driven by their exceptional characteristics, including long cycle life, high energy density, and environmental sustainability. These features make LIBs particularly desirable for a wide range of applications such as mobile electronic devices and electric cars. − Nonetheless, traditional graphite anodes have a lower theoretical capacity (372 mA h g –1 ) than silicon (Si), which offers an extremely high theoretical capacity (4200 mA h g –1 for Li 22 Si 4 ), rich resources, and a suitable operating voltage (≈0.4 V vs Li/Li + ), making Si one of the highest potential anode materials. ,− However, the commercialization of Si is constrained by the large volume expansion (≈300%) during the lithiation and delithiation processes, along with poor intrinsic conductivity leading to difficulties in achieving high-cycle performance. , As an alternative, silicon monoxide (SiO) has gained broader interest among researchers since they have a more suitable volume expansion (≈160%) due to the production of Li 2 O and lithium silicates. ,, Unfortunately, two crucial issues still need to be addressed. First, the volume expansion of SiO cannot be overlooked, as it results in the pulverization and detachment of electrode materials.…”

“…10,11 As an alternative, silicon monoxide (SiO) has gained broader interest among researchers since they have a more suitable volume expansion (≈160%) due to the production of Li 2 O and lithium silicates. 1,10,11 Unfortunately, two crucial issues still need to be addressed. First, the volume expansion of SiO cannot be overlooked, as it results in the pulverization and detachment of electrode materials.…”

“…2,6−9 However, the commercialization of Si is constrained by the large volume expansion (≈300%) during the lithiation and delithiation processes, along with poor intrinsic conductivity leading to difficulties in achieving highcycle performance. 10,11 As an alternative, silicon monoxide (SiO) has gained broader interest among researchers since they have a more suitable volume expansion (≈160%) due to the production of Li 2 O and lithium silicates. 1,10,11 Unfortunately, two crucial issues still need to be addressed.…”

A B- and F-enriched buffering interphase enables a high-rate and high-stability SiOx/C anode

“…As a newly emerging anode candidate for lithium-ion batteries (LIBs), silicon-suboxide/carbon composite (SiO x /C, 0 < x ≤ 2) materials are considered as one of the most promising high-capacity anode candidates for future large-scale industrialization, in view of their distinct advantages such as high theoretical capacity (1965–4200 mA h g −1 ) and low price. 1–3 However, many issues, such as slow lithium-ion diffusion kinetics, severe volume change (∼200%) due to the lithiation/delithiation process, and unavoidable generation of by-products (Li 2 O and lithium silicates) during the first discharge process have led to poor initial coulombic efficiency (ICE) and unsatisfactory cycling durability of SiO x /C anodes, seriously hindering their commercialization process. 3–5…”