Charged Insulating Skeleton-Enabled Deep Deposition and Robust Interface for Stable Lithium Metal Anodes.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Conductive 3D collectors for lithium metal anodes often result in uneven lithium deposition, leading to volume expansion and interface instability.
• This instability hinders the performance and longevity of lithium metal batteries.

Purpose of the Study:

• To design and fabricate a novel 3D collector for lithium metal anodes that promotes uniform, deep lithium deposition.
• To enhance the stability and cycle life of lithium metal batteries by mitigating dendrite growth and dead lithium formation.

Main Methods:

• A composite 3D collector (NGF@Cu) was designed using an insulating glass fiber skeleton and a conductive copper substrate.
• The collector was modified with amino silane to create positively charged insulating skeletons, regulating ion transport.
• Symmetrical and full lithium metal batteries (with NCM811 cathodes) were assembled and tested for cycling performance and lifespan.

Main Results:

• The NGF@Cu collector facilitated bottom-up deep lithium deposition, effectively utilizing the internal space.
• The modified collector ensured regulated anion distribution and rapid Li ion transport, forming robust LiF-rich SEI layers.
• Symmetrical batteries achieved over 1300 hours of lifespan, and full batteries demonstrated stable cycling over 300 cycles at 0.5 C with good high-rate capacity retention.

Conclusions:

• The developed charged insulating 3D collectors effectively guide deep lithium deposition and suppress dendrite formation.
• This approach significantly improves the energy density and reversibility of metal electrodes.
• The findings offer a promising strategy for advancing high-performance lithium metal batteries.