Customizing Pore Structure and Lithiophilic Sites Dual-Gradient Free-Standing 3D Lithium-Based Anode to Enable...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal anodes are crucial for high-energy-density batteries.
• Traditional 3D hosts suffer from uneven lithium deposition, leading to dendrites and reduced lifespan.
• Developing advanced 3D hosts is key to overcoming these limitations.

Purpose of the Study:

• To design and fabricate a novel dual-gradient 3D host (GDPL-3DH) for uniform lithium deposition.
• To investigate the synergistic effects of gradient pore structure and lithiophilic sites on lithium nucleation and growth.
• To evaluate the electrochemical performance of the GDPL-3DH in lithium-based symmetrical and full cells.

Main Methods:

• Electrospinning was used to construct the dual-gradient 3D host.
• Optical microscopy and scanning electron microscopy (SEM) were employed to observe lithium deposition patterns.
• Electrochemical testing, including galvanostatic cycling of symmetrical and full cells, was performed.

Main Results:

• The GDPL-3DH demonstrated a gradient-increased electrical conductivity.
• Uniform "bottom-top" lithium deposition was achieved, suppressing dendrite formation.
• Symmetrical cells exhibited an ultra-long lifespan of 5250 hours at 2 mA cm⁻².
• Full cells with various cathodes (LiFePO₄, S/C, LiNi₀.₈Co₀.₁Mn₀.₁O₂) showed excellent performance, with a LiFePO₄-based cell retaining 94.7% capacity after 700 cycles.

Conclusions:

• The dual-gradient strategy effectively regulates lithium deposition, enhancing battery safety and longevity.
• The GDPL-3DH offers a promising platform for practical lithium metal batteries.
• This approach provides new insights into controlling lithium nucleation and growth mechanisms.