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

Silicon suboxides (SiO x ) have been widely concerned as a practical anode material for the next-generation lithium-ion batteries due to their relatively high theoretical capacity and lower volume change compared to silicon (Si). Nevertheless, traditional binder poly(vinylidene difluoride) (PVDF) still cannot hold the integrity of the SiO x particle due to its weak van der Waals force. Herein, a copolymer binder for SiO x microparticles is synthesized through a facile method of free radical polymerization between acrylamide (AM) and acrylic acid (AA). By adjusting the mass ratio of the AM/AA monomer, the copolymer binder can generate a covalent–noncovalent network with superior elastic properties from the synergistic effect. During electrochemical testing, the SiO x anode with the optimal copolymer binder (AM/AA = 3:1) delivered a reversible capacity of 734 mAh g–1 (two times that of commercial graphite) at 0.5C after 300 cycles. Thus, this work developed a green and effective strategy for synthesizing a water-soluble binder for Si-based anodes.

Section: Introductionmentioning

confidence: 99%

Random Copolymer Hydrogel as Elastic Binder for the SiO_x Microparticle Anode in Lithium-Ion Batteries

Weng

Chen

et al. 2022

“…Recently, various binders have been explored to enhance the stability of silicon-based electrodes. − The results show that a high content of hydroxyl and carboxyl groups in binders can form strong interactions with the surface of silicon-based anodes. In addition, the high mechanical strength and self-healing properties of binders are necessary to accommodate the volumetric strain of electrodes.…”

Section: Introductionmentioning

confidence: 99%

Three-Dimensional Crosslinked PAA-TA Hybrid Binders for Long-Cycle-Life SiO_x Anodes in Lithium-Ion Batteries

Tang

Wei

et al. 2022

Self Cite

The large volume expansion hinders the commercial application of silicon oxide (SiO x ) anodes in lithium-ion batteries. Recent studies show that binders play a vital role in mitigating the volume change of SiO x electrodes. Herein, we introduce the small molecule tannic acid (TA) with high branching into the linear poly(acrylic acid) (PAA) binder for SiO x anodes. The three-dimensional (3D) crosslinked network with multiple hydrogen bonds is formed by the incorporation of abundant hydroxyl groups with unique carboxyl groups, which increases the interfacial adhesive strength with SiO x particles. As a consequence, SiO x electrodes based on the PAA-TA binder show an excellent cycling performance with a high specific capacity of 1025 mA h g–1 at 500 mA g–1 after 250 cycles. Moreover, the SiO x ||NCM811 full cell exhibits a reversible capacity of 143 mA h g–1 corresponding to 87.4% capacity retention after 100 cycles.

“…For anode materials, commercial graphite is the most widely applied anode, but its low theoretical capacity (372 mAh g –1 ) limits its further application for high-energy-density LIBs . In contrast, a Si anode possesses a high theoretical specific capacity of 4200 mAh g –1 and a low lithiation voltage plateau of <0.4 V vs Li/Li + , having been recognized as the most promising anode material for next-generation LIBs. , Unfortunately, the huge volume variation (∼300%) of the Si anode based on the alloying reaction pulverizes Si particles during the lithiation/delithiation process and leads to the continuous formation of a solid electrolyte interface (SEI), resulting in severe capacity fading. , Accordingly, nonstoichiometric SiO x (0 < x < 2) with mild volume fluctuation (∼118%) has been proposed and extensively studied . Through the lithiation of SiO x , irreversible Li 2 O and lithium silicates are generated .…”

Section: Introductionmentioning

confidence: 99%

Engineering High-Performance SiO_x Anode Materials with a Titanium Oxynitride Coating for Lithium-Ion Batteries

Lai

Wei

Zhou

et al. 2022

Self Cite

Micron-sized silicon oxide (SiO x ) has been regarded as a promising anode material for new-generation lithium-ion batteries due to its high capacity and low cost. However, the distinct volume expansion during the repeated (de)lithiation process and poor conductivity can lead to structural collapse of the electrode and capacity fading. In this study, SiO x anode materials coated with TiO 0.6 N 0.4 layers are fabricated by a facile solvothermal and thermal reduction technique. The TiO 0.6 N 0.4 layers are homogeneously dispersed on SiO x particles and form an intimate contact. The TiO 0.6 N 0.4 layers can enhance the conductivity and suppress volume expansion of the SiO x anode, which facilitate ion/electron transport and maintain the integrity of the overall electrode structure. The as-prepared SiO x -TiON-200 composites demonstrate a high reversible capacity of 854 mAh g −1 at 0.5 A g −1 with a mass loading of 2.0 mg cm −2 after 250 cycles. This surface modification technique could be extended to other anodes with low conductivity and large volume expansion for lithium-ion batteries.