Polyimide-cellulose interaction in Sb anode enables fast charging lithium-ion battery application

Antimony-based electrodes are promising as fast charging anodes for lithium-ion batteries because their operating potential is about 0.8 V vs. Li/Li⁺, far away from the plating potential of Li. However, their capacity decays fast due to large volume expansion, the issue which has often been addressed through the use of nano-sized materials. Herein, we utilize an ion-dipole interaction between polyimide and carboxymethyl cellulose which suppresses particle cracking and holds the particle together to enable antimony anodes utilizing micron-sized Sb particles for high rate applications. Sb anode with 9.4% polyimide coating exhibits a high reversible capacity of 580 mAh g⁻¹ at 1 A g⁻¹ with excellent cycle performance. The rate performance of the electrode can be further improved by adding 5% acetylene black during the polyimide coating process. Even at a current rate of 20 C (13.2 A g⁻¹), a highly reversible capacity of 380 mAh g⁻¹ can be obtained. The superior high-rate capability and excellent stability of Sb anodes are further verified by full-cell tests with LiFePO₄ cathodes.