Design of high-energy-dissipation, deformable binder for high-areal-capacity silicon anode in lithium-ion batteries

Although silicon has the highest theoretical capacity among the existing anode materials, its practical application is highly hindered by huge interface stress arising from large volume change upon cycling. Herein, an efficient energy-dissipation engineering was harnessed on high-capacity silicon anodes through a synergized "static" (chemically crosslinking) and "dynamic" (physically crosslinking) binder. In this dual network, the disassociation of non-covalent hydrogen bonds greatly facilitates the dispersion and release of unfavorable stress, while the permanent chemical bonding network enables a deformable network to sustain the electrode structure. Such a strategy effectively avoids both materials and electrodes deterioration and promises a better Si-based anode: a high areal capacity of 2 mAh cm−2 with capacity retention of 91.3% after 200 cycles. Meanwhile, the energy-dissipation mechanism was further clarified by temperature-dependent FTIR and finite element simulations.