3D Printing Technology Applied in Lithium Metal Batteries: From Liquid to Solid.
Abstract
Li-metal batteries are strongly considered to be one of the most promising candidates for high energy density energy storage devices in our modern society. However, the state-of-the-art Limetal batteries are still limited by several challenges including 1) low energy/power density; 2) Li dendrite growth; 3) low coulombic efficiency, and 4) safety concerns within the liquid electrolyte. This thesis mainly focuses on addressing these challenges by using a 3D printing technique to realize high energy/power density Li-metal batteries.
A self-standing high areal energy density cathode for Li-S battery was developed by the 3D printing method in the first part. The optimized porosity and conductivity of cathode design from macroscale to the nanoscale are beneficial for Li+/e- transport in a thick electrode. This work offers a new strategy to fabricate high sulfur loading cathodes and improve the electrochemical performance of advanced Li-S batteries.
However, Li+ transport is usually poor in thick cathodes, resulting in low capacity output, fast capacity decay, and large overpotential. To tackle the issue of thick sulfur cathodes, a thickness independent electrode structure is proposed in the second part which can transform a thick electrode into a combination of vertically aligned “thin electrodes”.
Apart from the cathode, Li anode also plays an important role in determining the Li-metal batteries performance. Herein, in the third part, a 3D-printed vertically aligned Li anode (3DP-VALi) is shown to efficiently guide Li deposition via a “nucleation within micro-channel walls” process, enabling a high-performance dendrite-free Li anode.
Issues like leakage, flammability, and electrochemical instability of liquid electrolytes have triggered safety issues as well as restrictions on the practical application of Li-metal batteries. Herein, in the fourth part, an ultra-high-energy/power density quasi-solid-state Li-Se battery was realized by combining a 3D-printed carbon nanotube interlayer with a high Se-loading gel polymer electrolyte-filled cathodes.
To achieve a high energy density all-solid-state Li metal battery, a dual vertically aligned electrodes structure with well-controlled microscale features is proposed in the fifth part to promote the development of fast charging all-solid-state Li metal battery.
In summary, these five parts in this thesis provide an important guide to achieve a high energy density Li metal battery by a 3D printing technique