A research team led by Prof. Mitch LI Guijun, Assistant Professor from the Division of Integrative Systems and Design at the Hong Kong University of Science and Technology (HKUST), has developed an innovative single-step laser printing technique to accelerate the manufacturing of lithium-sulfur batteries. Integrating the commonly time-consuming active materials synthesis and cathode preparation in a nanosecond-scale laser-induced conversion process, this technique is set to revolutionize the future industrial production of printable electrochemical energy storage devices. The findings of this study were recently published in the top journal Nature Communications.
香港科技大学（HKUST）综合系统与设计学部的助理教授李桂军（Mitch LI Guijun）教授领导的研究团队开发了一种创新的单步激光打印技术，以加速锂硫电池的制造。该技术将通常耗时的活性材料合成和正极制备整合到纳秒级激光诱导转化过程中，有望彻底改变未来可打印电化学储能设备的工业生产。这项研究的发现最近发表在顶级期刊《自然通讯》上。

Lithium-sulfur batteries are expected to supersede existing lithium-ion batteries due to sulfur cathodes' high theoretical energy density. To ensure the rapid conversion of sulfur species, these cathodes are typically composed of active materials, host materials (or catalysts), and conductive materials. However, the fabrication of host materials and preparation of sulfur cathodes often involve complicated, multistep, and labor-intensive processes that require varying temperatures and conditions, raising concerns about efficiency and cost in industrial production.
锂硫电池有望取代现有的锂离子电池，因为硫阴极具有较高的理论能量密度。为确保硫物种的快速转化，这些阴极通常由活性材料、宿主材料（或催化剂）和导电材料组成。然而，宿主材料的制造和硫阴极的制备往往涉及复杂、多步骤且劳动密集型的过程，需要不同的温度和条件，这引发了人们对工业化生产效率和成本的担忧。

To overcome these challenges, Prof. Li's team developed a novel single-step laser printing technique for the rapid manufacturing of integrated sulfur cathodes. During this high-throughput laser-pulse irradiation process, the precursor donor is activated, producing jetting particles that include in-situ synthesized halloysite-based hybrid nanotubes (host material), sulfur species (active material), and glucose-derived porous carbon (conductive component). The mixture is printed onto a carbon fabric acceptor, forming an integrated sulfur cathode. Notably, the laser-printed sulfur cathodes demonstrate outstanding performance in both coin and pouch lithium-sulfur cells.
为克服这些挑战，李教授的团队开发了一种新型单步激光打印技术，用于快速制造集成硫正极。在这一高通量激光脉冲辐照过程中，前驱体供体被激活，产生喷射粒子，其中包括原位合成的基于埃洛石的混合纳米管（宿主材料）、硫物种（活性材料）和葡萄糖衍生的多孔碳（导电组分）。该混合物被打印到碳纤维受体上，形成集成硫正极。值得注意的是，激光打印硫阴极在币和pouch锂硫电池中均表现出卓越的性能。

"Traditional manufacturing processes of a cathode/anode in ion battery usually contain the synthesis of active materials (sometimes combined with host material/ catalyst), the preparation of mixture slurry, and the assembly of cathode/anode. Prof. Li explained, "These steps are usually carried out separately under different temperatures and conditions because the materials behave differently. As a result, the whole process can take tens of hours or even several days."
离子电池正负极的传统制造工艺通常包括活性物质的合成（有时与主体材料/催化剂结合）、混合浆料的制备以及正负极的组装。李教授解释道：“这些步骤通常在不同的温度和条件下分别进行，因为材料的表现不同。因此，整个过程可能需要数十小时甚至数天。”

Prof. Li said, "Our newly developed laser-induced conversion technology offers a way to combine these processes into a single step at nanosecond speeds. The printing speed can achieve about 2 cm2/minute using only a single beam laser. A 75 × 45 mm2 sulfur cathode can be printed within 20 minutes and supply power for a small screen for several hours when assembled into a lithium-sulfur pouch cell."
李教授表示："我们新开发的激光诱导转化技术能以纳秒级速度将这些工艺整合为单步完成。采用单束激光时印刷速度可达约2平方厘米/分钟，75×45平方毫米的硫阴极可在20分钟内完成印刷，组装成锂硫软包电池后能为小屏幕供电数小时。"

Dr. YANG Rongliang, the first author of this work and former postdoctoral fellow at HKUST, added, "These intriguing findings generated from our study on laser-material interaction. The laser-induced conversion process can be characterized as an ultra-concentrated thermal phenomenon. The irradiated materials undergo a complex transient heating and cooling process, with theoretical transient temperatures reaching up to thousands of degrees Kelvin. The precursor materials decompose, and the decomposed particles recombine to form new materials. This ultra-concentrated thermal process not only enables the formation and combination of materials with different natures, but also drives the concomitant micro-explosions that facilitate the jetting and transferring of forming particles."
该工作的第一作者、香港科技大学前博士后研究员杨荣良博士补充道："这些有趣的发现源自我们对激光-物质相互作用的研究。激光诱导的转化过程可被描述为一种超集中热现象。被辐照材料会经历复杂的瞬态加热和冷却过程，理论瞬态温度可达数千开尔文。前驱体材料发生分解，分解后的粒子重新组合形成新材料。这种超浓缩热过程不仅能促使不同性质的材料形成与结合，还会引发伴随的微型爆炸，从而促进成型颗粒的喷射与转移。

Note: Dr. YANG Rongliang, a former postdoctoral fellow from the Division of Integrative Systems and Design at HKUST, is the first author, and Prof. Mitch LI Guijun at HKUST is the corresponding author. The research also received substantial support from Prof. TANG Aidong from Central South University China and the China University of Geosciences, and Senior Engineer LI Tianbao and Senior Engineer TU Feiyue from Changsha Research Institute of Mining and Metallurgy Co. LTD. The research is funded by Hong Kong Innovation Technology Commission (ITC) under project number MHP/060/21.
注：香港科技大学综合系统与设计学部前博士后研究员杨荣良博士为第一作者，香港科技大学李桂军教授为通讯作者。该研究还得到了中国中南大学唐爱东教授和中国地质大学（武汉）、长沙矿冶研究院有限公司高级工程师李天宝和高级工程师涂飞跃的大力支持。研究由香港创新科技署（ITC）资助，项目编号为MHP/060/21。