Hydrogen substituted graphdiyne as carbon-rich flexible electrode for lithium and sodium ion batteries

Ning Wang,Zeyi Tu,Xiangyan Shen,Jianjiang He,Lin Fu,Yuliang Li,Changshui Huang,Huiping Du,Zili Cui,Yuanping Yi,Ze Yang

doi:10.1038/s41467-017-01202-2

Abstract

Organic electrodes are potential alternatives to current inorganic electrode materials for lithium ion and sodium ion batteries powering portable and wearable electronics, in terms of their mechanical flexibility, function tunability and low cost. However, the low capacity, poor rate performance and rapid capacity degradation impede their practical application. Here, we concentrate on the molecular design for improved conductivity and capacity, and favorable bulk ion transport. Through an in situ cross-coupling reaction of triethynylbenzene on copper foil, the carbon-rich frame hydrogen substituted graphdiyne film is fabricated. The organic film can act as free-standing flexible electrode for both lithium ion and sodium ion batteries, and large reversible capacities of 1050 mAh g−1 for lithium ion batteries and 650 mAh g−1 for sodium ion batteries are achieved. The electrode also shows a superior rate and cycle performances owing to the extended π-conjugated system, and the hierarchical pore bulk with large surface area.

Highlights

Organic electrodes are potential alternatives to current inorganic electrode materials for lithium ion and sodium ion batteries powering portable and wearable electronics, in terms of their mechanical flexibility, function tunability and low cost
We synthesize a carbon-rich framework which is named as hydrogen substituted graphdiyne (HsGDY)
The results indicated the existence of small amount of C–O and C=O bonds on the surface of HsGDY samples

Summary

Introduction

Organic electrodes are potential alternatives to current inorganic electrode materials for lithium ion and sodium ion batteries powering portable and wearable electronics, in terms of their mechanical flexibility, function tunability and low cost. We synthesize a carbon-rich framework which is named as hydrogen substituted graphdiyne (HsGDY) It is applied as a flexible electrode for LIBs and SIBs. HsGDY is an extended π-conjugated carbon skeleton comprised of butadiyne linkages and benzene rings, while aromatic hydrogen (Ar-H) group of benzene ring is introduced to HsGDY to provide more active binding sites for Li/Na storage. HsGDY is an extended π-conjugated carbon skeleton comprised of butadiyne linkages and benzene rings, while aromatic hydrogen (Ar-H) group of benzene ring is introduced to HsGDY to provide more active binding sites for Li/Na storage This free-standing HsGDY film electrode can achieve a highly improved reversible capacity of 1050 mAh g–1 for LIBs and 650 mAh g–1 for SIBs at a current density of 100 mA g–1. This hierarchical porous structure with high π-conjugation of HsGDY leads to high rate performance and can reach 570 mAh g–1 for LIBs and 220 mAh g–1 for SIBs at the rate as high as 5 A g–1

Methods

Results

Conclusion