Liping Yue

Renewable and Superior Thermal-Resistant Cellulose-Based Composite Nonwoven as Lithium-Ion Battery Separator

A renewable and superior thermal-resistant cellulose-based composite nonwoven was explored as lithium-ion battery separator via an electrospinning technique followed by a dip-coating process. It was demonstrated that such nanofibrous composite nonwoven possessed good electrolyte wettability, excellent heat tolerance, and high ionic conductivity. The cells using the composite separator displayed better rate capability and enhanced capacity retention, when compared to those of commercialized polypropylene separator under the same conditions. These fascinating characteristics would endow this renewable composite nonwoven a promising separator for high-power lithium-ion battery.

Sustainable, heat-resistant and flame-retardant cellulose-based composite separator for high-performance lithium ion battery

A sustainable, heat-resistant and flame-retardant cellulose-based composite nonwoven has been successfully fabricated and explored its potential application for promising separator of high-performance lithium ion battery. It was demonstrated that this flame-retardant cellulose-based composite separator possessed good flame retardancy, superior heat tolerance and proper mechanical strength. As compared to the commercialized polypropylene (PP) separator, such composite separator presented improved electrolyte uptake, better interface stability and enhanced ionic conductivity. In addition, the lithium cobalt oxide (LiCoO2)/graphite cell using this composite separator exhibited better rate capability and cycling retention than that for PP separator owing to its facile ion transport and excellent interfacial compatibility. Furthermore, the lithium iron phosphate (LiFePO4)/lithium cell with such composite separator delivered stable cycling performance and thermal dimensional stability even at an elevated temperature of 120°C. All these fascinating characteristics would boost the application of this composite separator for high-performance lithium ion battery.

Taichi-inspired rigid-flexible coupling cellulose-supported solid polymer electrolyte for high-performance lithium batteries

Inspired by Taichi, we proposed rigid-flexible coupling concept and herein developed a highly promising solid polymer electrolyte comprised of poly (ethylene oxide), poly (cyano acrylate), lithium bis(oxalate)borate and robust cellulose nonwoven. Our investigation revealed that this new class solid polymer electrolyte possessed comprehensive properties in high mechanical integrity strength, sufficient ionic conductivity (3 × 10−4 S cm−1) at 60°C and improved dimensional thermostability (up to 160°C). In addition, the lithium iron phosphate (LiFePO4)/lithium (Li) cell using such solid polymer electrolyte displayed superior rate capacity (up to 6 C) and stable cycle performance at 80°C. Furthermore, the LiFePO4/Li battery could also operate very well even at an elevated temperature of 160°C, thus improving enhanced safety performance of lithium batteries. The use of this solid polymer electrolyte mitigates the safety risk and widens the operation temperature range of lithium batteries. Thus, this fascinating study demonstrates a proof of concept of the use of rigid-flexible coupling solid polymer electrolyte toward practical lithium battery applications with improved reliability and safety.

High-voltage and free-standing poly(propylene carbonate)/Li6.75La3Zr1.75Ta0.25O12 composite solid electrolyte for wide temperature range and flexible solid lithium ion battery

Solid electrolyte is regarded as a perfect way to enhance safety issues and boost energy density of lithium batteries. Herein, we developed a type of free-standing poly(propylene carbonate)/Li6.75La3Zr1.75Ta0.25O12 composite solid electrolyte for ambient temperature and flexible solid-state lithium batteries. The composite solid electrolyte exhibited excellent comprehensive performance in terms of high ionic conductivity (5.2 × 10−4 S cm−1) at 20 °C, a wide electrochemical window (4.6 V), high ionic transference number (0.75) and satisfactory mechanical strength (6.8 MPa). When evaluated as solid electrolyte for an ambient-temperature solid lithium battery, such a composite electrolyte delivered excellent rate capability (5C) at 20 °C. This superior performance can be comparable to a liquid electrolyte-soaked PP separator-based lithium battery at room temperature. To our knowledge, this is the best rate capability of a solid composite electrolyte for a solid lithium battery at ambient temperature. Moreover, such a composite electrolyte-based flexible LiFePO4/Li4Ti5O12 lithium ion battery delivered excellent rate capability and superior cycling stability. All these fascinating features make poly(propylene carbonate)/Li6.75La3Zr1.75Ta0.25O12 a very promising all-solid-state electrolyte for flexible solid lithium batteries. Our study makes a big step into addressing the challenges of ambient-temperature solid lithium batteries.

A high-voltage poly(methylethyl α-cyanoacrylate) composite polymer electrolyte for 5 V lithium batteries

High-voltage lithium batteries have attracted increasing attention for large scale energy storage application in electric vehicles, smart grids and other electronic devices. However, a major bottleneck to achieve high-voltage lithium batteries is the anodic voltage stability of electrolytes. Herein, we fabricate a composite polymer electrolyte, comprised of poly(methylethyl α-cyanoacrylate), nonwoven polytetrafluoroethylene and lithium bis(oxalate)borate salt. The composite polymer electrolyte presents a wide electrochemical window, which is explored to address the above-mentioned bottleneck. It is demonstrated that such a composite polymer electrolyte exhibits a higher ionic conductivity (1.24 mS cm−1 at 25 °C), better dimensional thermal resistance (150 °C) and higher ion transference number (0.63) compared to those of commercially available liquid electrolytes with a polypropylene separator. In addition, LiNi0.5Mn1.5O4/Li batteries employing such a composite polymer electrolyte deliver excellent cycling performance and outstanding rate capability. So, it is demonstrated that the poly(methylethyl α-cyanoacrylate) based polymer electrolyte appears to be a promising candidate of high-voltage lithium battery electrolyte towards next generation high energy density batteries.

In Situ Formation of Polysulfonamide Supported Poly(ethylene glycol) Divinyl Ether Based Polymer Electrolyte toward Monolithic Sodium Ion Batteries

Sodium ion battery is one of the promising rechargeable batteries due to the low-cost and abundant sodium sources. In this work, a monolithic sodium ion battery based on a Na3 V2 (PO4 )3 cathode, MoS2 layered anode, and polyether-based polymer electrolyte is reported. In addition, a new kind of polysulfonamide-supported poly(ethylene glycol) divinyl ether based polymer electrolyte is also demonstrated for monolithic sodium ion battery via in situ preparation. The resultant polymer electrolyte exhibits relatively high ionic conductivity (1.2 mS cm-1 ) at ambient temperature, wide electrochemical window (4.7 V), and favorable mechanical strength (25 MPa). Moreover, such a monolithic Na3 V2 (PO4 )3 /MoS2 sodium ion battery using this polymer electrolyte delivers outstanding rate capability (up to 10 C) and superior cyclic stability (84%) after 1000 cycles at 0.5 C. What is more essential, such a polymer electrolyte based soft-package monolithic sodium ion cell can still power a red light emitting diode lamp and run finite times without suffering from any internal short-circuit failures, even in the case of a bended and wrinkled state. Considering these aspects, this work no doubt provides a new approach for the design of a high-performance polymer electrolyte toward monolithic sodium ion battery with exceptional rate capability and high safety.

Sustainable and Superior Heat-Resistant Alginate Nonwoven Separator of LiNi0.5Mn1.5O4/Li Batteries Operated at 55 °C

High-voltage lithium-ion batteries have become a major research focus. As a major part of lithium batteries, the separator plays a critical role in the development of high-voltage lithium batteries. Herein, we demonstrated a sustainable and superior heat-resistant alginate nonwoven separator for high-voltage (5 V) lithium batteries. It was demonstrated that the resultant alginate nonwoven separator exhibited better mechanical property (37 MPa), superior thermal stability (up to 150 °C), and higher ionic conductivity (1.4 × 10-3 S/cm) as compared to commercially available polyolefin (PP) separator. More impressively, the 5 V class LiNi0.5Mn1.5O4 (LNMO)/Li cell with this alginate nonwoven separator delivered much better cycling stability (maintaining 79.6% of its initial discharge capacity) than that (69.3%) of PP separator after 200 cycles at an elevated temperature of 55 °C. In addition, the LiFePO4/Li cell assembled with such alginate nonwoven separator could still charge and discharge normally even at an elevated temperature of 150 °C. The above-mentioned fascinating characteristics of alginate separator provide great probability for its application for high-voltage (5 V) lithium batteries at elevated temperatures.