Improved swelling behavior of Li ion batteries by microstructural engineering of anode

Swelling behavior of the graphite electrode hinders the increase in volumetric density of Li ion batteries as the free space in the cell is necessary to ensure battery safety by accommodating the volume change of the anode associated with Li ions. Here, we report a simple electrode microstructural engineering strategy to control swelling behavior of the anode by employing a two-step pressing process. Two-step pressing enables the uniform distribution of the pores throughout the electrode without cracking or pulverization of the active material. The anode prepared by a two-step pressing process under an optimized condition exhibits superior swelling behavior (4.47% swelling after 25 cycles) compared to that of the anode prepared with a one-step pressing process (5.00% swelling after 25 cycles). The electrochemical properties could be also further improved due to a uniform pore distribution and enhanced adhesion strength.