Solution-processed PDMS/SWCNT porous electrodes with high mass loading: toward high performance all-stretchable-component lithium ion batteries†
Stretchable lithium ion batteries receive considerable attention due to their promising application to meet the growing demand of wearable portable electronics. Despite tremendous efforts being made to fabricate stretchable lithium ion batteries, challenges remain due to the complicated fabrication process, high fabrication cost, and low mass loading. Herein, a simple design concept for all-stretchable-component lithium ion batteries via an all solution process is reported. All components are stretchable, including Li4Ti5O12 (LTO) and LiFePO4 (LFP) electrodes based on the 3D polydimethylsiloxane (PDMS)/single-wall carbon nanotube (SWCNT) porous framework, poly(vinylidene fluoride-co-hexa-fluoropropylene) (PVDF-HFP) gel separator, and PDMS package. The prepared electrodes based on the versatile 3D PDMS/SWCNT porous framework show many superior merits, such as high mass loading, good stretchability, outstanding mechanical durability, and high conductivity. More impressively, the mass loading of our electrode materials is as high as 7 mg cm−2, which is higher than that of all the reported all-stretchable-component lithium ion batteries. The resulting practical capacity is improved significantly up to 0.81 mA h cm−2 at 0.069C. The full cell delivers a high capacity of 0.66 mA h cm−2 even after 100 stretch–release cycles of 50% tensile strain at 0.075C, and shows a stable power supply during various extreme deformations. This work opens a feasible route to construct all-stretchable-component lithium ion batteries with high electrochemical performance and high stretchability, presenting promising potential for application in new-generation wearable and portable energy storage devices.