Solid-state corrosion of lithium for prelithiation of SiO_(x)-C composite anode with carbon-incorporated lithium phosphorus oxynitride

In order to address the issues of low initial Coulombic efficiency of SiO_(x)-C composite anode due to the formation of solid electrolyte interphase,irreversible conversion reaction,and large volume change,the prelithiation method using metal lithium has been employed as one of effective solutions.However,violent side reactions with liquid electrolyte for prelithiation lead to low prelithiation efficiency and induce poor interface between the SiO_(x)-C electrode and liquid electrolyte.Here,a new prelithiation method with so called solid-state corrosion of lithium is developed.By replacing liquid electrolyte with solid-state electrolyte of carbon-incorporated lithium phosphorus oxynitride(LiCPON),not only various side reactions associated with metal lithium are avoided,but also the perfect interface is achieved from the decomposition products of LiCPON.The successful implementation of solid-state corrosion prelithiation can be confirmed by changes in optical image,scanning electron microscopy,and X-ray diffraction.Compared with pristine electrode,the initial Coulombic efficiency of the prelithiated electrode using solid electrolyte can be increased by about 10%,reaching 98.6%in half cell and 88.9%in full cell.Compared with prelithiated electrode using liquid electrolyte,the prelithiation efficiency of the prelithiated anode with solid-state corrosion can be increased from 25.7%to 82.8%.Solid-state corrosion of lithium is expected to become a useful method for prelithiation of SiO_(x)-C composite electrode with high initial Coulombic efficiency and large prelithiation efficiency.

Dendrite-free all-solid-state lithium batteries with lithium phosphorous oxynitride-modified lithium metal anode and composite solid electrolytes

Dendrite formation on lithium (Li) metal anode is a key issue which hinders the development of rechargeable Li battery seriously. A novel method for suppress!ng Li dendrites via using Li phosphorous oxynitride (UPON) modified Li anode and Li1.5Al0.5Ge1.5(PO4)3-poly(ethylene oxide)(Li bistrifluoromethane-sulfonimide)(LAGP-PEO(LiTFSI)) composite solid electrolyte in all-solid-state Li battery is proposed, and the effect of the thickness of UPON on Li anode performarice is also studied. LiPON film with a thickness of 500 nm exhibits satisfactory interface property between Li metal anode and the LAGP-PEO(LiTFSI) solid electrolyte. The LiPON film provides a uniform Li^+ flux across the interface and effectively inhibits the formation of Li dendrites in all-solid-state Li batteries. The assembled all-solid-state Li cell Li(LiPON)/LAGP-PEO(LiTFSI)/LiFePO4 delivers an initial discharge capacity of 152.4 mAh·g^-1 and exhibits good cycling stability and rate performanee at 50 ℃.

全固态薄膜锂/锂离子电池的研究进展

本文介绍了全固态薄膜锂/锂离子电池发展;对全固态薄膜锂/锂离子电池最近的研究进展进行了综述分析,并指出了今后研究的方向。

Constructing stable Li-solid electrolyte interphase to achieve dendrites-free solid-state battery:A nano-interlayer/Li prereduction strategy

Solid-state batteries based on Li and nonflammable solid-state electrolytes(SSEs)have aroused the attention of numerous researchers because of their absolute safety and potentially high energy density.Most SSEs after coming into contact with Li are reduced,which leads to high interfacial charge-transfer impedance and dendrites formation.In this study,an“interlayer-Li pre-reduction strategy”was proposed to solve the above problem of reduction.An intermediate layer was introduced between solid electrolyte and Li,and it reacted with Li to produce a stable and ion-conductive interphase.Cubic garnet-type Nb-doped Li_(7)La_(3)Zr_(2)O_(12)(Nb-LLZO)was selected as an example solid electrolyte since it is characterized by high ionic conductivity,feasible preparation under ambient conditions,as well as low cost.The high impedance arising from the reduction at the Nb-LLZO|Li interface has limited its application.In this paper,a nano-scale Li phosphorus oxynitride(LiPON)layer was deposited on the Nb-LLZO pellets through radio frequency(RF)magnetron sputtering,which pre-reacted with Li in-situ to produce a lithiophilic,electronically insulating,and ionic conductive interphase.The produced interphase significantly inhibited the reduction of Nb5+against Li and the formation and propagation of Li dendrites.It is noteworthy that Li|LiPON|Nb-LLZO|LiPON|Li cells stably cycled for over 2,000 h without any short circuit.This study emphasizes and demonstrates the significance of the pre-conversion of modification layer between unstable SSE and Li metal to improve interfacial stability.