Challenges, laser processing and electrochemical characteristics on application of ultra-thick electrode for high-energy lithium-ion battery

Lithium ion battery with ultra-thick electrode is hardly manufactured in practice due to its poor rate capability and large unusable capacity caused by high internal resistances in spite of the potential benefits of a high capacity and cost reduction by less inactive material usage in the same volume. In this work, we report the effectiveness of laser structuring of ultra-thick electrodes for high-energy battery. Lithium cobalt-oxide cathode (700 mu m) and graphite anode (650 mu m) are prepared with the areal discharge capacity, 25 mAh cm(-2). After laser structuring, electrode surface morphology and chemistry are investigated. Internal resistances and diffusion characteristics are analyzed by electrochemical impedance spectroscopy using symmetric cells with nonintercalating salt. Geometric changes of ultra-thick electrode by laser structuring contributes to decrease of tortuosity, decrease of electronic and ionic resistances, and enhancement of diffusion characteristics in both laser-structured cathode and anode without chemically negative reaction, thermal damage or a failure of electrode structure. The rate capability and areal discharge capacity of laser-structured cells increases by 5 times than that of unstructured one at 0.1 C condition. Therefore, laser structuring of ultra-thick electrodes is a viable approach for the high-energy battery with practical use of space.

Automated summary

The study demonstrates that laser structuring of ultra-thick electrodes can improve the efficiency and performance of high-energy batteries by reducing internal resistances and enhancing diffusion characteristics, leading to increased capacity and cost savings.