Collaborative Research: Fundamental Studies of Na-Ion Storage in Hard Carbon

非技术摘要与锂离子电池相比，钠离子电池具有重要的优势：与锂电池不同，钠资源丰富，价格低廉，而且不会在地理上集中。有足够的钠来经济地提供大规模应用所需的电池数量，如电网级别的能量存储和全球向电动汽车的过渡。这些特性使钠离子电池有可能克服目前阻碍风能和太阳能等间歇性可再生能源广泛采用的障碍。实现钠离子电池的主要科学障碍在于负极方面，硬碳是最有前途的负极材料之一。从蔗糖、纤维素和泥炭苔藓等丰富的前体中可以廉价地合成硬碳电极。在材料研究部固态和材料化学项目的支持下，研究团队致力于提供了解，以释放这些材料的潜力，并指导钠离子电池的未来发展。更广泛地说，这项研究产生的知识丰富了我们对碳材料的总体理解，并可能开创一个新的研究前沿，为其他应用量身定做非石墨碳材料。在教育层面上，该项目为研究生提供了高度合作的材料化学培训机会。通过在俄亥俄州立大学建立良好的大学前外联活动，该项目还融合了代表不足的K-12学生，以激发他们对科学、工程和技术的兴趣。技术摘要钠与锂具有许多与生俱来的化学性质，使钠离子电池(NIB)具有与著名的锂离子电池(LIB)相似的特性。然而，除了其他方面的差异外，Na离子比Li离子大得多，所以许多Li离子的存储机制都不适用于Na离子。PI的初步结果表明，普遍存在于硬碳中的钠储存模型与系统的实验结果不一致。随之而来的知识鸿沟阻碍了下一代NIB的实现，因此PI致力于阐明硬碳中钠离子储存的基本机制的新模型，并对该模型进行测试。这项研究旨在实现三个目标：(1)对硬碳的结构产生详细的原子水平的理解。(2)阐明了钠离子在硬质碳中的嵌入机理。(3)经验性检验，新模型能够预测硬质炭的物理化学性质与NiB中相应的电化学行为之间的关系。为了实现这些目标，研究团队汇集了硬碳合成和电化学表征、材料的高级原子和形态表征以及碳结构的原子建模方面的专业知识。

Non-technical AbstractSodium-ion batteries have important advantages over lithium-ion batteries: unlike lithium, sodium is abundant, inexpensive, and is not geographically concentrated. There is sufficient sodium to provide economically the quantity of batteries needed for large-scale applications such as grid-level energy storage and for a global transition to electric vehicles. These qualities give sodium-ion batteries the potential to overcome the barriers that currently prevent the widespread adoption of intermittent renewable energy sources such as wind and solar power. The principal scientific obstacle for the realization of sodium-ion batteries lies on the anode side, where hard carbon is one of the most promising anode materials. Hard carbon electrodes can be synthesized cheaply from abundant precursors such as sucrose, cellulose, and peat moss. With the support of the Solid State and Materials Chemistry program in the Division of Materials Research, the research team work to provide the understanding to unlock the potential of these materials and guide the future development of sodium-ion batteries. More broadly, the knowledge generated with this research enriches our general understanding of carbon materials and could initiate a new research frontier tailoring non-graphitic carbon materials for other applications. On an educational level, this project provides highly collaborative training opportunities in materials chemistry for graduate students. Through well-established pre-college outreach activities at OSU, this project also integrates under-represented K-12 students in order to inspire their interests in science, engineering and technology. Technical AbstractSodium shares many innate chemical properties with lithium, giving sodium-ion batteries (NIBs) similar characteristics to the well-known lithium-ion batteries (LIBs). However, Na ions are much larger than Li ions besides other differences, so many of the mechanisms for Li-ion storage are not applicable to Na ions. The PIs' preliminary results show that the prevailing model of Na storage in hard carbon is inconsistent with systematic experimental results. The attendant knowledge gap is holding back the realization of next generation NIBs, and thus the PIs work to elucidate the new model of basic mechanisms of Na-ion storage in hard carbon and test the model. The research is conducted to accomplish three goals: (1) Generate detailed atomic level understanding of the structure of hard carbons. (2) Elucidate the underpinning mechanisms of Na-ion insertion in hard carbon. (3) Test empirically that the new model is predictive of the relationship between the physicochemical properties of hard carbon and the corresponding electrochemical behavior in NIBs. To achieve the goals, the team of investigators brings together expertise in synthesis and electrochemical characterization of hard carbon, advanced atomistic and morphological characterization of materials, and atomistic modeling of carbon structures.