基于一体化正极与电解质膜的高性能固态电池（英文）

High Performance Solid-state Battery with Integrated Cathode and Electrolyte

固态锂电池(SSLBs)因其高能量密度和出色的安全性而备受关注。然而,电极和电解质之间的较大的界面阻抗是阻碍SSLBs发展的关键问题之一。在这项工作中,我们通过同时静电纺丝和静电喷雾的方法制备了一体化的聚丙烯腈(PAN)电解质和LiFePO4正极膜(PAN-LFP)。通过这种方法制备的PAN-LFP膜具有很好的柔性,并且正极和电解质之间是紧密接触的。把此一体化的PAN-LFP膜与锂金属负极组装成的固态Li|PAN-LFP电池,具有很小的极化和优异的界面稳定性。在0.1C的电流下固态Li|PAN-LFP电池能够放出160.8 mAh·g^-1的比容量,并且在0.2C的电流下循环500次后仍保持81%的初始容量。此外,所得的固态Li|PAN-LFP电池即使在破坏性实验中也能够正常工作(例如弯曲、剪切),显示出优异的安全性能。

Lithium ion batteries(LIBs)are becoming the most popular energy storage systems in our society.However,frequently occurring accidents of electrical cars powered by LIBs have caused increased safety concern regarding LIBs.Solid-state lithium batteries(SSLBs)are believed to be the most promising next generation energy storage system due to their better in-built safety mechanisms than LIBs using flammable organic liquid electrolyte.However,constructing the ionic conducting path in SSLBs is challenging due to the slow ionic diffusion of Li ion in solid-state electrolyte,particularly in the case of solid-solid contact between the solid materials.In this paper,we demonstrate the construction of an integrated electrolyte and cathode for use in SSLBs.An integrated electrolyte and cathode membrane is obtained via simultaneous electrospinning and electrospraying of a polyacrylonitrile(PAN)electrolyte and a LiFePO4(LFP)cathode material respectively,for the cathode layer,followed by the electrospinning of PAN to prepare the electrolyte layer.The resultant integrated PAN-LFP membrane is flexible.Scanning electron microscopy and energy dispersive X-ray spectroscopy measurement results show that the electrode and electrolyte are in close contact with each other.After the integrated PAN-LFP membrane is filled with a succinonitrile-bistrifluoromethanesulfonimide(SN-LiTFSI)salt mixture,it is paired with a lithium foil metal anode electrode,and the resultant solid-state Li|PAN-LFP cell exhibits limited polarization and outstanding interfacial stability during long term cycling.That is,the Li|PAN-LFP cell presents a specific capacity of 160.8 mAh g 1 at 0.1C,and 81%of the initial capacity is maintained after 500 cycles at 0.2C.The solid-state Li|PAN-LFP cell also exhibits excellent resilience in destructive tests such as cell bending and cutting.