Stable Silicon Anode for Lithium-Ion Batteries through Covalent Bond Formation with a Binder via Esterification

Abstract

Silicon (Si) is considered to be one of the most promising anode candidates for next-generation lithium-ion batteries because of its high theoretical specific capacity and low discharge potential. However, its poor cyclability, caused by tremendous volume change during cycling, prevents commercial use of the Si anode. Herein, we demonstrate a high-performance Si anode produced via covalent bond formation between a commercially available Si nanopowder and a linear polymeric binder through an esterification reaction. For efficient ester bonding, polyacrylic acid, composed of −COOH groups, is selected as the binder, Si is treated with piranha solution to produce abundant −OH groups on its surface, and sodium hypophosphite is employed as a catalyst. The as-fabricated electrode exhibits excellent high rate capability and long cycle stability, delivering a high capacity of 1500 mA h g–1 after 500 cycles at a high current density of 1000 mA g–1 by effectively restraining the susceptible sliding of the binder, stabilizing the solid electrolyte interface layer, preventing the electrode delamination, and suppressing the Si aggregation. Furthermore, a full cell is fabricated with as-fabricated Si as an anode and commercially available LiNi0.6Mn0.2Co0.2O2 as a cathode, and its electrochemical properties are investigated for the possibility of practical use.

Advances of polymer binders for silicon‐based anodes in high energy density lithium‐ion batteries

“…Copyright 2011, American Chemical Society. (C) Schematic illustration of esterification reaction between PAA and the hydroxyl groups on the surface of SiNPs, and the long‐term cycling performances of SiNP anodes with hydrogen bonded, partially esterified and fully esterified PAA binders 77 . Copyright 2019, American Chemical Society…”

“…(C) Schematic illustration of esterification reaction between PAA and the hydroxyl groups on the surface of SiNPs, and the long-term cycling performances of SiNP anodes with hydrogen bonded, partially esterified and fully esterified PAA binders. 77 Copyright 2019, American Chemical Society surface of SiNPs. Later, Komaba et al demonstrated that SiO anode with PAA binder showed the best performances compared to that of PVDF, PVA or CMC binders (Figure 5B).…”

Ultrathin Silicon Nanolayer Implanted NixSi/Ni Nanoparticles as Superlong‐Cycle Lithium‐Ion Anode Material

“…[ 19 ] Similarly, by introducing mechanically robust covalent bonding between Si nanopowder and a linear polymeric binder through an esterification reaction a stable Si anode was reported. [ 23 ] However, combined with conductive additives, binders reduce the silicon content, which results in lowering of the actual calculated specific capacity of the anode and thereby limits the silicon anodes from providing high energy density. To alleviate this issue, a binder‐free, flexible, and free‐standing electrode comprising 92% silicon content was designed by the self‐rolling of cellulose nanosheets.…”

A Comprehensive Review of Li-Ion Battery Materials and Their Recycling Techniques

“…SiO is presumed to be an alternative for silicon as an anode material because of its high specific capacity (>1600 mA h g −1 ). Further, coordination of oxygen with lithium involves a minimal volume change in Figure 12 and simultaneously low activation of energy [140][141][142][143].…”

“…SiO is presumed to be an alternative for silicon as an anode material because of its high specific capacity (>1600 mA h g −1 ). Further, coordination of oxygen with lithium involves a minimal volume change in Figure 12 and simultaneously low activation of energy [140][141][142][143]. The reactions of electrochemistry that occur at the time of the discharge process cause SiO conversion to Si, lithium oxides that can form Si-Li or, the major forms of an alloy of Si-Li and also the silicates of lithium.…”