Preparation of Current Collectors with Uniform Multi-Pits by Physical Rolling for Improving Full Battery Rate Performance

Reasonable design and modification of the current collector's surface is an important means to improve the rate performance of a full battery. However, despite considerable structural engineering efforts focused on current collectors, these modifications are still challenging to apply in actual production for various reasons. To solve these problems, a low-cost physical rolling method is used to produce an Al foil with uniform multi-pits for the current collector (PEAL) of the electrode. The pits formed by this method increase the effective contact area of the current collector, thus increasing the electron collection capacity and slurry loading capacity. The improved adhesion of the electrode leads to a reduction in the amount of binder, further increasing the electron migration rate. The results show that full battery with PEAL as current collector has higher rate performance (867.5 mAh at 15C) and higher ultrafast cycling stability (1005.8 mAh with the capacity retention of 76.1% at 10C after 1000 cycles) than other samples. The rate performance of the full battery is further improved (increase from 867.5 mAh to 962.4 mAh at 15C) by reducing the binder ratio from 2.5% to 1.9%.