In-Situ Polymerized Binder: A Three-in-One Design Strategy for All-Integrated SiOx Anode with High Mass Loading in Lithium Ion Batteries

The development of SiOx electrode with high mass loading, which is an important prerequisite for practical lithium-ion batteries, remains an arduous challenge by using existing binders. Herein, we propose a three-in-one design strategy for binder systems in all-integrated SiOx electrodes. "Hard" poly(furfuryl alcohol) (PFA) and "soft" thermoplastic polyurethane (TPU) are interweaved into 3D conformation to confine SiOx particles via in-situ polymerization. In the electrode system, PFA works as a framework and TPU servers as a buffer, and H-bonding interactions are formed between the components. Benefiting from the three-pronged collaborative strategy, PFA-TPU/SiOx electrode exhibits an areal capacity of 2.4 mAh cm–2 at a high mass loading of >3.0 mg cm–2 after 100 cycles. Such a binder system is also extended to other potential metal oxides anode with high mass loading, e.g., Fe2O3 and SnO2, thus shedding light on rational design of functional polymer binders for high-areal-capacity electrodes.