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 SiO x 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 SiO x electrodes. “Hard” poly(furfuryl alcohol) (PFA) and “soft” thermoplastic polyurethane (TPU) are interweaved into 3D conformation to confine SiO x 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/SiO x 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., Fe 2 O 3 and SnO 2, thus shedding light on rational design of functional polymer binders for high-areal-capacity electrodes.