All-solid-state lithium-ion batteries (ASSLIBs) owing to their advantage of enhanced safety are considered to be a promising candidate for next-generation energy storage devices. However, the poor cycling performance and low areal capacities of ASSLIBs with S, Li2S or traditional oxide cathodes hinder the development of high-energy-density ASSLIBs. Herein, a Li6PS5Cl solid-state electrolyte has been systematically investigated for use as a cathode active material in ASSLIBs for the first time. ASSLIBs employing Li6PS5Cl as both the active material and electrolyte with a Li–In alloy anode are fabricated. A Li6PS5Cl-based cell with an active material loading of 3.1 mg cm−2 exhibits a high discharge capacity of around 535 mA h g−1 after 650 cycles at 56 mA g−1 (∼0.1C) at room temperature, which is the highest value among ASSLIBs using sulfide SSEs as active materials and is even comparable with those of cells with S, Li2S or transition metal sulfides as the active material. This superior long-term cycling performance is attributed to the highly reversible electrochemical activity of Li6PS5Cl revealed by ex situ XRD and XPS analyses.
Peng Li,Lianyi Shao,Pengfei Wang,Xi Zheng,Haoxiang Yu,Shangshu Qian,Miao Shui,Nengbing Long,Jie Shu
In this work, Li 2 NaV 2 (PO 4 ) 3 is successfully synthesized by using a simple solid-state reaction method. Structural analysis shows that this sample is a hybrid product consisted of rhombohedral Li 3 V 2 (PO 4 ) 3 phase and rhombohedral Na 3 V 2 (PO 4 ) 3 phase As a cathode material for lithium ion batteries, Li 2 NaV 2 (PO 4 ) 3 exhibits an initial reversible capacity of 108.9 mAh g −1 at 35 mA g −1 in the potential range between 3.0 and 4.3 V, with an average working potential at 3.75 V. The lithium-ion diffusion coefficient in Li 2 NaV 2 (PO 4 ) 3 is measured to be 1.86–3.27 × 10 −15 cm 2 s −1 . In addition, the electrochemical reaction between Li 2 NaV 2 (PO 4 ) 3 and Li is also investigated by various in-situ and ex-situ techniques. Viewed from the in-situ and ex-situ results, it is concluded that the electrochemical reactions of Li 2 NaV 2 (PO 4 ) 3 with Li are associated with the formation of rhombohedral LiV 2 (PO 4 ) 3 phase and rhombohedral NaV 2 (PO 4 ) 3 phase during the lithium ion extraction process and its reverse lithium insertion process is reversible for structural evolution. The highly stable structure ensures the electrochemical reversibility of Li 2 NaV 2 (PO 4 ) 3 cathode material in lithium ion batteries.
危险品化学品经营许可证（带存储）