A modified multi-crosslinking starch as a high-performance binder for silicon-based anodes in lithium-ion batteries

An intensive attention is paid to silicon (Si), due to its high theoretical specific capacity (4200 mAh g −1 ) and natural abundance, among the anode materials for lithium-ion batteries. However, bonding failure and structural fracture of the anodes caused by the huge volume expansion (300 %) of Si during repeated lithiation-delithiation cycles, results in dramatic capacity degradation and lifetime attenuation of lithium-ion batteries. Herein, a modified starch binder (TADS) was synthesized by introduction of different polar groups to enhance the hydrogen bonding and adhesion among the binder, Si anodes and the current collector. The Si electrode with the TADS binder (Si-TADS) exhibited superior mechanical integrity and electrochemical performance, delivering a high reversible specific capacity of 2005.9 mAh g −1 at 0.1C after 100 cycles, more than twice that of the counterpart with the unmodified starch binder (Si-TA, 947.5 mAh g −1 ). Furthermore, a Si-based anode with an initial capacity of 1000 mAh g −1 sustained over 600 stable cycles when using the TADS binder, whereas only 150 cycles were achieved with the unmodified TA binder.