Enhanced electrochemical and thermal behavior of lithium-ion batteries with ultrathick electrodes via oriented pores

The increasingly extensive application scale compels the development of lithium-ion batteries toward higher energy densities to eliminate endurance anxiety. Developing ultrathick electrodes to compress the proportion of inactive components is the most direct strategy to improve battery energy densities, although overshadowed by the enthusiasm of searching for new chemistry; however, sluggish ion transport kinetics, especially at high discharge rates, is the main challenge faced by thick electrodes. Here, we demonstrate two variants of oriented pore structures to enable ion fast transport in thick electrodes, and develop a quasi-3D electrochemical-thermal coupled model for lithium-ion batteries based on an open-source computational fluid dynamics platform to investigate their electrochemical and thermal behavior. The results show that the oriented pore electrodes yield an over 2-fold increase in the areal energy density of full-cells at the high discharge rate of 3C, and have a more uniform local distribution of Li ions in both electrolyte and electrodes. Meanwhile, the heat generation rate of battery can be reduced clearly due to their lower ohm resistance. Additionally, a comprehensive critical parameter analysis of oriented pores is performed with the aim of providing a further understanding for ultra-thick electrodes that can help maximize the areal energy density of full-cells.