Accelerating lithium-ion pre-desolvation and transport via glassy MOF for fast-charging and high-energy-density lithium-ion batteries

TL;DR

A new glassy metal-organic framework improves lithium-ion battery charging speed and energy density, promising faster EV charging and longer battery life.

Contribution

Introduces a glassy MOF coating for graphite anodes that accelerates lithium-ion pre-desolvation and transport.

Findings

MOF glass-coated graphite enables ultrafast lithium-ion diffusion and stable interphase formation.

Full cells with glass@graphite anodes retain 88% capacity after 1000 cycles at 4 C.

A 2.36 Ah pouch cell achieves 283 Wh/kg energy density with over 80% capacity retention after 300 cycles.

Abstract

Conventional graphite anodes in lithium-ion batteries (LIBs) suffer from limited fast-charging capability and lithium dendrite growth, particularly at high current densities. This work introduces a glassy metal-organic framework (MOF glass) that simultaneously enables easy lithium-ion pre-desolvation and fast Li⁺ transport. The MOF glass-coated graphite (glass@graphite) forms a distinctive double-layer structure during initial discharge: an electron-insulating outer layer with rigid 2.93 Å pores that facilitates easy Li⁺ pre-desolvation, and a Li₃P-rich inner layer that ensures rapid lithium-ion conduction. The outer layer's pre-desolvation effect generates a highly aggregated electrolyte within MOF channels, promoting formation of a stable anion-derived LiF-dominated solid electrolyte interphase. The resulting partially desolvated Li⁺ species readily penetrate the ion-conducting inner layer, enabling ultrafast diffusion. When coupled with LiNi0.8Co0.1Mn0.1O2 (NCM-811) cathodes, the NCM-811//glass@graphite full cells demonstrate remarkable fast-charging performance (88% capacity retention after 1000 cycles at a high current of 4 C). A practical 2.36 Ah pouch cell achieves an energy density of 283 Wh/kg while maintaining over 80% capacity after 300 cycles. This approach presents a transformative strategy for developing fast-charging, high-energy-density LIBs.

Glassy MOFs overcomes graphiteas slow desolvation bottleneck in lithium-ion batteries, paving the way for electric vehicle batteries that charge in minutes and last much longer per charge.

Figures