Revisit the Progress of Binders for a Silicon-Based Anode from the Perspective of Designed Binder Structure and Special Sized Silicon Nanoparticles

Abstract

Si-based anodes have the advantages of high energy density and abundant reserve. However, their severe volume change during the charge–discharge process leads to particles’ pulverization and electrode destruction, which hinder their commercial application. Nanostructured Si is effective at relieving the expansion strain, and binders with a small proportion have been proven to play a pivotal role in maintaining the Si-based electrode integration. Si nanoparticles of various sizes show different particuological behaviors, including distribution, aggregation, etc. Moreover, the binders with specific molecular structure also have unique bonding characteristics with Si particles of different sizes. Except the aforementioned aspects, the process techniques of Si nanoparticles and binders also greatly affect the electrode. Though some pioneering reviews about the progress of binders for Si-based anodes have been published, in order to boost the practical application of Si-based anodes, it is urgent to revisit the previous investigations to clarify the correlation of the particle size, binder structure, and process techniques.

Self‐Repairable Silicon Anodes Using a Multifunctional Binder for High‐Performance Lithium‐Ion Batteries

“…Although the binder is self-healable, it does not necessarily guarantee the self-healability of the entire Si anode under battery operating conditions due to the limited binder content in anodes, usually less than 20 wt.%. [11,17,27,29] Additionally, under the battery operating conditions, an anode is in contact with an electrolyte solution. Therefore, ideally, the entire Si anode in the electrolyte should be capable of self-healing in electrolytes under battery operating conditions.…”

“…To address aforementioned issues and enhance the cycle life of Si anodes, several approaches have been developed, including the design of nanostructured Si (porous, yolk-shell, nanowires, and nanomesh), [10][11][12] artificial SEI layer, [13] composites, [14,15] electrolytes, [16] and binders. [17,18] Proper design of binders is particularly crucial for Si anodes because binders affect the structural integrity and mechanical stability of Si anodes. Unfortunately, the most widely used polyvinylidene fluoride (PVDF) binder is unsuitable for Si anodes, showing fast capacity decay due to its insufficient mechanical properties and weak van der Waals interaction with Si.…”

Understanding the Role of Polymer Interactions within Binders in Composite Lithium-Ion Anodes

“…This annealing step can induce Fischer esterification-like bonding , between −COOH and −OH groups found at various particle–binder and binder–binder interfaces. Further studies have addressed other design considerations of effective electrode binder selection for use in high-capacity anodes such as structural design through incorporation of nanostructural and molecular motifs, , conductivity enhancements through utilization of conductive polymers, , and thermal stability through use of thermoresponsive polymeric systems …”

“…This annealing step can induce Fischer esterification-like bonding 26,30 between −COOH and −OH groups found at various particle−binder and binder−binder interfaces. Further studies have addressed other design considerations of effective electrode binder selection for use in high-capacity anodes such as structural design through incorporation of nanostructural and molecular motifs, 31,32 conductivity enhancements through utilization of conductive polymers, 33,34 and thermal stability through use of thermoresponsive polymeric systems. 35 In addition to single-component polymeric binders, multicomponent blends offer opportunities to tune the mechanical properties of a composite electrode via deliberate modification of the interconnected networks between particles, which could in turn enhance anode electrochemical performance.…”

How to Promote the Industrial Application of SiOx Anode Prelithiation: Capability, Accuracy, Stability, Uniformity, Cost, and Safety

“…It results in poor cycle performance and seriously hinders the wide application of Si. [78][79][80][81][82][83][84][85][86][87][88][89][90] Under the background that Si encounters great challenges in practical applications, SiO x attracts researchers' attention with more comprehensive properties. [39,[91][92][93][94][95][96][97][98][99] Compared with SiO x anode with high energy density and superior stability is expected to meet the demand of the rapidly developed electric vehicles' market.…”