Gradient H‐Bonding Binder Enables Stable High‐Areal‐Capacity Si‐Based Anodes in Pouch Cells

Abstract

Alleviating large stress is critical for high‐energy batteries with large volume change upon cycling, yet this still presents a challenge. Here, a gradient hydrogen‐bonding binder is reported for high‐capacity silicon‐based anodes that are highly desirable for the next‐generation lithium‐ion batteries. The well‐defined gradient hydrogen bonds, with a successive bond energy of −2.88– −10.04 kcal mol−1, can effectively release the large stress of silicon via the sequential bonding cleavage. This can avoid recurrently abrupt structure fracture of traditional binder due to lack of gradient energy dissipation. Certainly, this regulated binder endows stable high‐areal‐capacity silicon‐based electrodes >4 mAh cm−2. Beyond proof of concept, this work demonstrates a 2 Ah silicon‐based pouch cell with an impressive capacity retention of 80.2% after 700 cycles (0.028% decay/cycle) based on this gradient hydrogen‐bonding binder, making it more promising for practical application.

Interface‐Adaptive Binder Enabled by Supramolecular Interactions for High‐Capacity Si/C Composite Anodes in Lithium‐Ion Batteries

“…To address the above mentioned issues, numerous multifunctional Si‐based binders, with strongly adhesive, [ 19,20 ] self‐healing, [ 21–23 ] energy‐dissipation, [ 24–27 ] and other abilities, [ 28 ] have been proposed. Basically, adhesion is crucial to ensure the cohesion of electrode components (e.g., active material and conductive agent), thereby contributing to the mechanical stability and long‐term cycling performance of electrode.…”

“…[11][12][13] Nevertheless, the inevitable particle pulverization, electrode destruction, and unstable solid electrolyte interphase (SEI) layer caused by inherent volume variation of Si still remain, especially at higher-energy-densities, resulting in the battery performance of these Si/C anodes far below the industrial criteria. [14,15] To address the above mentioned issues, numerous multifunctional Si-based binders, with strongly adhesive, [19,20] self-healing, [21][22][23] energy-dissipation, [24][25][26][27] and other abilities, [28] have been proposed. Basically, adhesion is crucial to ensure the cohesion of electrode components (e.g., active material and conductive agent), thereby contributing to the mechanical stability and long-term cycling performance of electrode.…”

Constructing Self‐Adapting Electrostatic Interface on Lithium Metal Anode for Stable 400 Wh kg−1 Pouch Cells

“…High cell-level energy density targeting 500 Wh kg −1 cannot be accomplished unless realistic conditions are used: high loading cathode (>4 mAh cm −2 ), lean electrolytes (<3 g Ah −1 ), and low N/P ratio (<2). [41][42][43][44] To our best knowledge, the cell with large capacity, high-energy-density, and long cycle life has not been demonstrated in literatures yet.…”

An Ion‐Conductive Grafted Polymeric Binder with Practical Loading for Silicon Anode with High Interfacial Stability in Lithium‐Ion Batteries

“…The parameters of Si particles before and after fully lithiation are based previous reports. [ 2c,36 ] Spherical Si nanoparticles (80−120 nm) are randomly distributed in the GG and GG‐g‐PAM binder before lithiation, respectively. During the lithiation process, Si nanoparticles undergo huge volume expansion with the intercalation of Li ions, which causes unavoidable stress concentration.…”

“…Although previous reports have demonstrated the excellent electrochemical performance of some soft‐packed full batteries based on silicon‐graphite anodes, few works have reported full pouch cells using pure silicon anodes. [ 36,37 ] As far as we know, the stable cycling performance of the 1 Ah‐level pouch cell based on pure Si anode by simply applying a binder has never been reported. Pouch cells with different capacities were prepared by pairing the Si@GG‐g‐PAM anodes with NCM523 cathodes.…”