Dataset underlying paper and thesis chapter: Analysis of gasification biochar from lignocellulosic waste for high performance biographite anode

Raw data of paper Analysis of gasification biochar from lignocellulosic waste for high performance biographite anode. Summary:Renewable graphite from low-grade waste is an alternative for fossil-derived graphite for anodes in lithium-ion batteries. There are various thermochemical processes available for producing battery grade biographite. The biochar coming from gasifiers is currently considered to have limited usefulness, despite its carbon-rich composition. In this study we focus on the biochar by-product of gasification from a novel 50 kWth Indirectly Heated Bubbling Fluidized Bed Steam Reformer (IHBFBSR) design, which is treated with a graphitization step. The high crystallinity and good initial performance make it a mature candidate for use as raw material in lithium ion batteries. The resulting graphitized biochar (biographite) is characterized by using X-ray crystallography, scanning electron microscopy, X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy to assess its crystallinity, morphology, surface composition and subsurface composition respectively. The material is tested in half cell batteries for use in lithium-ion batteries. The graphite has a high crystallinity which is necessary for good lithium diffusivity in the lattice structure. Also 96% of the theoretical graphite capacity in lithium-ion batteries is found. The biographite flakes are however non homogeneous in size. Also in battery half cells the material shows capacity fade linked to exfoliation of the material. The initial coulombic efficiency (ICE) during charging is lower than conventional graphites due to surface reactivity. Size distribution, exfoliation and ICE must therefor be addressed to make the IHBFBSR biographite fit for battery utility. <br><br>

《用于高性能生物石墨负极的木质纤维素废料气化生物炭分析》论文原始数据集

研究概述：由低阶废料制备的可再生石墨，可替代锂离子电池（lithium-ion batteries）负极所用的化石基石墨。当前已有多种热化学工艺可用于制备电池级生物石墨。尽管气化所得生物炭富含碳元素，但目前普遍认为其应用价值有限。本研究聚焦于一款新型50 kWth间接加热鼓泡流化床蒸汽重整器（Indirectly Heated Bubbling Fluidized Bed Steam Reformer, IHBFBSR）所产生的气化生物炭副产物，并对其实施石墨化处理。该生物炭具备高结晶度与优异的初始性能，可作为锂离子电池负极的成熟原材料候选。本研究通过X射线晶体学（X-ray crystallography）、扫描电子显微镜（scanning electron microscopy）、X射线光电子能谱（X-ray photoelectron spectroscopy）与能量色散X射线光谱（energy dispersive X-ray spectroscopy），分别对所得石墨化生物炭（生物石墨，biographite）的结晶度、形貌、表面组成与亚表面组成进行表征。将该材料组装于锂离子电池半电池中开展性能测试：该石墨具备高结晶度，这是在其晶格结构中实现优异锂扩散能力的必要条件；其在锂离子电池中可达到理论石墨容量的96%。但该生物石墨片的尺寸分布并不均匀，在电池半电池测试中还出现了与材料剥离相关的容量衰减现象。充电阶段的首次库仑效率（Initial Coulombic Efficiency, ICE）低于传统石墨，这源于其较高的表面反应活性。因此，需针对性优化尺寸分布、剥离问题与首次库仑效率，才能使IHBFBSR生物石墨满足电池应用需求。