An Endotenon Sheath-Inspired Double-Network Binder Enables Superior Cycling Performance of Silicon Electrodes

Abstract

Silicon (Si) has been regarded as an alternative anode material to traditional graphite owing to its higher theoretical capacity (4200 vs. 372 mAh g−1). However, Si anodes suffer from the inherent volume expansion and unstable solid electrolyte interphase, thus experiencing fast capacity decay, which hinders their commercial application. To address this, herein, an endotenon sheath-inspired water-soluble double-network binder (DNB) is presented for resolving the bottleneck of Si anodes. The as-developed binder shows excellent adhesion, high mechanical properties, and a considerable self-healing capability mainly benefited by its supramolecular hybrid network. Apart from these advantages, this binder also induces a Li3N/LiF-rich solid electrolyte interface layer, contributing to a superior cycle stability of Si electrodes. As expected, the DNB can achieve mechanically more stable Si electrodes than traditional polyacrylic acid and pectin binders. As a result, DNB delivers superior electrochemical performance of Si/Li half cells and LiNi0.8Co0.1Mn0.1O2/Si full cells, even with a high loading of Si electrode, to traditional polyacrylic acid and pectin binders. The bioinspired binder design provides a promising route to achieve long-life Si anode-assembled lithium batteries. "Image missing"

Regulating the Solvation Structure of Li+ Enables Chemical Prelithiation of Silicon-Based Anodes Toward High-Energy Lithium-Ion Batteries

“…Currently, sustained research efforts have been dedicated to optimizing and heightening its electrochemical property. Considering the production costs, complex synthetic procedures, and actual application scenarios, the designs of multi-level conductivity carbon skeletons for silicon-based materials would be an effective way to realize industrialization [5,[14][15][16][17][18]. However, a routine amorphous coating layer has a lower conductivity than crystalline carbon.…”

Graphite-SiOxElectrodes with a Biopolymeric Binder for Li-Ion Batteries: Predicting the Cycle Life Performance from Physical Properties

“…SiO x is less conductive than graphite (6.7 × 10 –4 S cm –1 compared to ∼10 4 S cm –1 ) and thus a conductive 3D network with carbon black, or alternative conductive additives, is used to increase the electrically conductive pathways and enable the electron transfer from the surface of the electrode to the current collector. − In addition, the presence of the polymeric binder also increases the resistivity of the coatings despite its importance toward the mechanical stability of the electrode, and thus its presence is preferred at a minimum . Its role is to bind the active materials and conductive additive to the current collector and affect the electrode-current collector adhesion properties. , In order to reduce cost and improve the environmental impact of Li-ion battery electrodes, water-soluble binders can be utilized, most commonly carboxyl methylcellulose (CMC) and styrene-butadiene rubber (SBR). ,− The ideal binder should allow the volume expansion of the active mass during lithiation/delithiation cycles and augment the pulverization of the electrode and thus the failure of the battery after many charge/discharge cycles . Other polymeric natural or bioinspired binders like carrageenan have been introduced and electrochemically investigated in the literature in the past decade. − Among other similar water-based binders, carrageenan has the potential to replace the commonly used oil-based SBR, thus simplifying the electrode manufacturing in a more environmentally friendly way, without compromising the mechanical flexibility required .…”

“…8,21−23 The ideal binder should allow the volume expansion of the active mass during lithiation/delithiation cycles and augment the pulverization of the electrode and thus the failure of the battery after many charge/discharge cycles. 24 Other polymeric natural or bioinspired binders like carrageenan have been introduced and electrochemically investigated in the literature in the past decade. 25−28 a more environmentally friendly way, without compromising the mechanical flexibility required.…”

Lithium Vanadium Oxide/Graphene Composite as a Promising Anode for Lithium-Ion Batteries

“…Moreover, the Li + intercalation potential of graphite is low (0.1 V), which leads to lithium dendrites easily forming during charge and discharge, resulting in irreversible lithium loss and battery safety issues. Therefore, the development of novel anode materials with high-capacity, safe Li + intercalation potential, and long cycle life such as silicon [ 14 ], metal oxide [ 15 ], transition metal oxides [ 16 ] have attracted more and more attention.…”