Covalently Bonded Si–Polymer Nanocomposites Enabled by Mechanochemical Synthesis as Durable Anode Materials

Soltani

Advanced Energy Materials

et al. 2022

To date, lithium-ion batteries (LIBs) as one of the most promising means of energy storage have witnessed progressive upgrades of cell energy density and cost reduction, enabling, for example, longer EVs travel ranges (>300 km/charge) and deeper penetration of renewables into grid electricity. Despite the fast growing market of LIBs [3] and the worldwide conspicuous rise in LIBs production, the practical specific energy density of prevailing LIBs adopting graphite anode is approaching its theoretical limit, that is, ≈250 Wh kg −1 when paired with high-energy ceramic cathode such as nickel cobalt manganese oxides. Nevertheless, to meet the everpresent relentless demand from end-users such as portable electronics and EVs, the battery ought to be upgraded to provide 400-500 Wh kg −1 , 700-800 Wh L −1 with lower cost (<9.5 US cents/Wh, expected in 2030), and fast charge capabilities (>2C, i.e., fully charged within 1/2 h). [4] To achieve these goals, the core strategy for developing next-generation LIBs is to exploit higher-capacity battery materials that are cheap and abundant.Silicon (Si) is recognized to be one of the most appealing choices of anode materials due to its inherent low-cost, natural abundance, and the ultrahigh theoretical capacity of 3590 mAh g −1 (based on Li 15 Si 4 ) at low potential (<0.4 V vs Li/ Li + ). [5] Pioneering battery manufacturers like CATL and Tesla have Due to its uniquely high specific capacity and natural abundance, silicon (Si) anode for lithium-ion batteries (LIBs) has reaped intensive research from both academic and industrial sectors. This review discusses the ongoing efforts in tailoring Si particle surfaces to minimize the cycle-induced changes to the integral structure of particles or electrodes. As an upgrade or alternative to conventional coatings (e.g., carbons), the emerging organic moieties on Si offer new avenues toward tuning the interactions with various battery components that are key to electrochemical performances. The recent progress on understanding Si surfaces is reviewed with an emphasis on newly emerged diagnostic tools, which increasingly points to the critical role of organic components in stabilizing Si. The detailed analysis on the chemistry-structure-performance relationships in Si surface are discussed and the successful cases demonstrating the functions of the organic layers are provided, that is, via tailored interactions toward electrolyte or binder or conductive agents, are recapped. Various synthetic strategies for designing the surface organic layers are discussed and compared, highlighting the versatility and tunability of surface organic chemistry. The holistic considerations and promising research directions are summarized, shedding light on in-depth understanding and engineering Si surface chemistry toward practical LIBs application.

Section: Organic Surface Chemistry: Emerging Solutions To Practical S...mentioning

confidence: 99%

Section: Wwwadvancedsciencenewscommentioning

confidence: 99%

Emerging Organic Surface Chemistry for Si Anodes in Lithium‐Ion Batteries: Advances, Prospects, and Beyond

Soltani

Advanced Energy Materials

et al. 2022

“…Polyvinyl alcohol (PVA) is a flexible polymer with higher elasticity and tensile strength, which can change with the volume change of silicon particles during circulation. Shi et al [180] . used reactive high‐energy ball milling technique to design a PVA coated silicon nanoparticle composite (Figure 32a).…”

Section: Conducting Polymers Coating Layermentioning

confidence: 99%

Research Progress on Coating Structure of Silicon Anode Materials for Lithium‐Ion Batteries

Liu

Guan

et al. 2021

ChemSusChem

Silicon, which has been widely studied by virtue of its extremely high theoretical capacity and abundance, is recognized as one of the most promising anode materials for the next generation of lithium‐ion batteries. However, silicon undergoes tremendous volume change during cycling, which leads to the destruction of the electrode structure and irreversible capacity loss, so the promotion of silicon materials in commercial applications is greatly hampered. In recent years, many strategies have been proposed to address these shortcomings of silicon. This Review focused on different coatings materials (e. g., carbon‐based materials, metals, oxides, conducting polymers, etc.) for silicon materials. The role of different types of materials in the modification of silicon‐based material encapsulation structure was reviewed to confirm the feasibility of the protective layer strategy. Finally, the future research direction of the silicon‐based material coating structure design for the next‐generation lithium‐ion battery was summarized.

“…[ 50–56 ] Therefore, conventional Si‐based full cells usually have limited energy densities, poor lifetime and operating security, which will restrict their further applications in daily life. [ 57,58 ] In order to develop high‐energy Si‐based full cells with superior lifetime and enhanced security, a comprehensive battery system theory needs to be established, including the structural optimization of Si, [ 59–63 ] SiO x , [ 64–66 ] and Si‐alloy [ 67–69 ] anode materials, the selection of cathode materials with high capacities and voltage limits, the design principles of promising electrolytes, [ 70–74 ] binders, [ 75–78 ] and separators, [ 79–81 ] as well as their applications in half and full cells (such as LiCoO 2 (LCO)||Si, [ 69,82 ] LiFePO 4 (LFP)||Si, [ 83,84 ] LiNi x Co y Mn z O 2 (NCM, x + y + z = 1)||Si, [ 85–87 ] and S||Li x Si [ 88,89 ] ). State‐of‐the‐art pre‐lithiation technology focuses on further improving the energy densities and lifetime of Si‐based full cells, due to its powerful ability to compensate for irreversible Li + consumption.…”

Section: Introductionmentioning

confidence: 99%

“…[50][51][52][53][54][55][56] Therefore, conventional Si-based full cells usually have limited energy densities, poor lifetime and operating security, which will restrict their further applications in daily life. [57,58] In order to develop high-energy Si-based full cells with superior lifetime and enhanced security, a comprehensive battery system theory needs to be established, including the structural optimization of Si, [59][60][61][62][63] SiO x , [64][65][66] and Si-alloy [67][68][69] anode materials, the selection of cathode materials with high capacities and voltage limits, the design principles of promising electrolytes, [70][71][72][73][74] binders, [75][76][77][78] and separators, [79][80][81] as well as their applications in half and full cells (such as LiCoO 2 (LCO)||Si, [69,82] LiFePO 4 (LFP)||Si, [83,84] LiNi x Co y Mn z O 2 (NCM,…”

mentioning

confidence: 99%

Silicon‐Based Lithium Ion Battery Systems: State‐of‐the‐Art from Half and Full Cell Viewpoint

Guo

Dong

Wang

et al. 2021

Adv Funct Materials

Lithium‐ion batteries (LIBs) have been occupying the dominant position in energy storage devices. Over the past 30 years, silicon (Si)‐based materials are the most promising alternatives for graphite as LIB anodes due to their high theoretical capacities and low operating voltages. Nevertheless, their extensive volume changes in battery operation causes the structural collapse of Si‐based electrodes, as well as severe side reactions. In this review, the preparation methods and structure optimizations of Si‐based materials are highlighted, as well as their applications in half and full cells. Meanwhile, the developments of promising electrolytes, binders and separators that match Si‐based electrodes in half and full cells have made great progress. Pre‐lithiation technology has been introduced to compensate for irreversible Li+ consumption during battery operation, thereby improving the energy densities and lifetime of Si‐based full cells. More importantly, almost all related mechanisms of Si‐based electrodes in half and full cells are summarized in detail. It is expected to provide a comprehensive insight on how to develop high‐performance Si‐based full cells. The work can help us understand what happens during the lithiation process, the primary causes of Si‐based half and full cells failure, and strategies to overcome these challenges.