Application of PVDF Organic Particles Coating on Polyethylene Separator for Lithium Ion Batteries

Fabrication electro-spun Poly(vinyl alcohol)-Melamine nonwoven membrane composite separator for high-power lithium-ion batteries

Current commercial separators used in lithium-ion batteries have inherent flaws, especially poor thermal stability, which pose substantial safety risks. This study introduces a high-safety composite membrane made from electrospun poly(vinyl alcohol)-melamine (PVAM) and polyvinylidene fluoride (PVDF) polymer solutions via a dip coating method, designed for high-voltage battery systems. The poly(vinyl alcohol) and melamine components enhance battery safety, while the PVDF coating improves lithium-ion conductivity. The dip-coated PVDF/Esp-PVAM composite separators were evaluated for electrolyte uptake, contact angle, thermal stability, porosity, electrochemical stability and ionic conductivity. Notably, our Dip 1 % PVDF@Esp-PVAM composite separator exhibited excellent wettability and a lithium-ion conductivity of approximately 7.75 × 10⁻⁴ S cm⁻1 at room temperature. These separators outperformed conventional PE separators in half-cells with Ni-rich NCM811 cathodes, showing exceptional cycling stability with 93.4 % capacity retention after 100 cycles at 1C/1C, as compared to 84.8 % for PE separators. Our Dip 1 % PVDF@Esp-PVAM composite separator demonstrates significant potential for enhancing the long-term durability and high-rate performance of lithium-ion batteries, making it a promising option for long-term energy storage applications.

All-in-All: Dead Lithium-Ion Battery to Active Lithium-Ion Capacitor

Here, we have developed lithium-ion capacitors (LICs) with all the components, except the electrolyte solution, effectively recycled from the spent Lithium-ion batteries (LIBs). Hybrid capacitors, such as LICs, are potential breakthroughs in electrochemical energy storage devices, where most research is focused. These devices can simultaneously guarantee high energy and power by hybridizing battery-type and capacitive-type electrodes with two different reaction mechanisms. We have successfully upcycled the graphite, current collector, separator, etc., from the spent LIBs to fabricate a high-performance LIC. Our LIC consists of recovered graphite (RG) coated over recovered copper foil as an anode, recycled polypropylene as the separator, and reduced graphene oxide (rGO) synthesized from RG as the cathode. The RG half-cell exhibited an excellent specific capacity of 302 mAh g-1 even after 75 charge-discharge cycles with a coulombic efficiency of >99 %. The Li/rGO displayed remarkable cycling performance for over 1000 cycles with high stability and reversibility. Subsequently, the pre-lithiated RG (p-RG) electrode is paired with the rGO electrode under the balanced loading conditions to construct LIC, rGO/p-RG, delivering a maximum energy density of 185 Wh kg-1 with ultra-long durability of more than 10,000 cycles. The possibility of LIC under different climatic conditions is also explored, and its remarkable performance under various temperature conditions is worth mentioning.

Eco-Friendly Lithium Separators: A Frontier Exploration of Cellulose-Based Materials

Lithium-ion batteries, as an excellent energy storage solution, require continuous innovation in component design to enhance safety and performance. In this review, we delve into the field of eco-friendly lithium-ion battery separators, focusing on the potential of cellulose-based materials as sustainable alternatives to traditional polyolefin separators. Our analysis shows that cellulose materials, with their inherent degradability and renewability, can provide exceptional thermal stability, electrolyte absorption capability, and economic feasibility. We systematically classify and analyze the latest advancements in cellulose-based battery separators, highlighting the critical role of their superior hydrophilicity and mechanical strength in improving ion transport efficiency and reducing internal short circuits. The novelty of this review lies in the comprehensive evaluation of synthesis methods and cost-effectiveness of cellulose-based separators, addressing significant knowledge gaps in the existing literature. We explore production processes and their scalability in detail, and propose innovative modification strategies such as chemical functionalization and nanocomposite integration to significantly enhance separator performance metrics. Our forward-looking discussion predicts the development trajectory of cellulose-based separators, identifying key areas for future research to overcome current challenges and accelerate the commercialization of these green technologies. Looking ahead, cellulose-based separators not only have the potential to meet but also to exceed the benchmarks set by traditional materials, providing compelling solutions for the next generation of lithium-ion batteries.

Plasma Surface Treatment of Cu Current Collectors for Improving the Electrochemical Performance of Si Anodes

The practical utilization of Si electrodes is hindered by their substantial volume expansion during alloying and dealloying processes, which causes mechanical damage and separation from Cu current collectors. To alleviate the problem of Si composite detachment from Cu current collectors, the surface of the Cu current collectors is modified using atmospheric oxygen plasma. Plasma treatment improves the wetting ability of the Cu current collectors and, consequently, the coating quality of the Si electrodes. The uniform distribution of the Si electrode components reduces the sheet resistance and improves the adhesion properties of the Si electrodes containing surface-modified Cu current collectors. As a result, the volume expansion of Si during alloying and dealloying is reduced; this results in an excellent rate capability of 1584 mA h g-1 at a current density of 3.6 A g-1 (135% that of bare Cu) and excellent cycle performance of 1545 mA h g-1 after 300 cycles (Si electrodes with bare Cu exhibit 930 mA h g-1). Therefore, the developed plasma treatment method for Cu current collectors is expected to be an economical and efficient approach for improving the Li-ion battery performance.

Partially Neutralized Polyacrylic Acid as an Efficient Binder for Aqueous Ceramic-Coated Separators for Lithium-Ion Batteries

A partially neutralized polyacrylic acid (Pn-PAA) is used for coating sub-micron-sized α-alumina on a conventional microporous polyolefin separator, fabricating a ceramic-coated separator (CCS). Pn-PAA acts as a dispersant and binder by adsorbing itself on alpha(α)-alumina surfaces under acidic condition through the columbic interaction, providing a repulsive force to disperse fine alumina in aqueous suspension, and binds alumina strongly on plasma-treated separator through hydrogen bonding. This CCS shows favorable wettability in carbonate-based liquid electrolyte and ionic conduction due to the high hydrophilicity of Pn-PAA and alumina. With that, this study found that Pn-PAA-made-CCS yields a substantial adhesion strength of ~106 N/m with enhanced cycle stability, a specific capacity of 145.0 mAh/g after 200 cycles at 1 C at room temperature in half cells (LFP/Li metal).

Engineering Polymer-Based Porous Membrane for Sustainable Lithium-Ion Battery Separators

Due to the growing demand for eco-friendly products, lithium-ion batteries (LIBs) have gained widespread attention as an energy storage solution. With the global demand for clean and sustainable energy, the social, economic, and environmental significance of LIBs is becoming more widely recognized. LIBs are composed of cathode and anode electrodes, electrolytes, and separators. Notably, the separator, a pivotal and indispensable component in LIBs that primarily consists of a porous membrane material, warrants significant research attention. Researchers have thus endeavored to develop innovative systems that enhance separator performance, fortify security measures, and address prevailing limitations. Herein, this review aims to furnish researchers with comprehensive content on battery separator membranes, encompassing performance requirements, functional parameters, manufacturing protocols, scientific progress, and overall performance evaluations. Specifically, it investigates the latest breakthroughs in porous membrane design, fabrication, modification, and optimization that employ various commonly used or emerging polymeric materials. Furthermore, the article offers insights into the future trajectory of polymer-based composite membranes for LIB applications and prospective challenges awaiting scientific exploration. The robust and durable membranes developed have shown superior efficacy across diverse applications. Consequently, these proposed concepts pave the way for a circular economy that curtails waste materials, lowers process costs, and mitigates the environmental footprint.