Fast-chargeable lithium-ion batteries by μ-Si anode-tailored full-cell design

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Silicon anodes promise higher energy density and faster charging for lithium-ion batteries (LIBs).
• Commercialization is hindered by significant silicon volume expansion during full charge/discharge cycles.
• Traditional cell engineering faces challenges in utilizing silicon anodes effectively.

Purpose of the Study:

• To design a novel anode-tailored full-cell design (ATFD) for LIBs using micrometer-sized silicon (μ-Si) anodes.
• To enable stable and high-performance operation of μ-Si anodes within a limited, prespecified state-of-charge (SOC) range.
• To improve gravimetric energy density and fast-charging capabilities of LIBs.

Main Methods:

• Developed an anode-tailored full-cell design (ATFD) utilizing micrometer-sized silicon (μ-Si) anodes.
• Operated the μ-Si anode within a limited SOC range (30-70%) to manage volume changes.
• Evaluated cell performance, including energy density and cycle stability, compared to graphite-based cells.

Main Results:

• The ATFD-based cell achieved 21.3% higher gravimetric energy density than graphite counterparts in 18650 cells.
• Demonstrated 84.6% capacity retention after 500 cycles, even at a 3 C fast-charging rate.
• Homogeneous (de)lithiation and acceptable volume change were observed within the limited SOC range.

Conclusions:

• Partial, intermediate SOC operation of μ-Si anodes is a viable strategy for enhancing LIB performance.
• This approach significantly increases energy density and fast-charging capability.
• The ATFD offers a promising solution for overcoming the limitations of silicon anodes in commercial LIBs.