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

与锂离子电池相比，钠离子电池具有重要的优势：与锂不同，钠资源丰富，价格低廉，并且在地理上不集中。 有足够的钠可以经济地提供大规模应用所需的电池数量，如电网级储能和全球向电动汽车的过渡。 这些品质使钠离子电池有可能克服目前阻碍广泛采用间歇性可再生能源（如风能和太阳能）的障碍。 实现钠离子电池的主要科学障碍在于阳极侧，其中硬碳是最有前途的阳极材料之一。 硬碳电极可以廉价地从丰富的前体如蔗糖、纤维素和泥炭藓合成。 在材料研究部门的固态和材料化学计划的支持下，研究团队致力于提供理解，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一般理解，并可能启动一个新的研究前沿，为其他应用定制非石墨碳材料。 在教育层面上，该项目为研究生提供了材料化学方面的高度合作培训机会。 通过在俄勒冈州立大学完善的大学预科推广活动，该项目还整合了代表性不足的K-12学生，以激发他们对科学，工程和技术的兴趣。钠与锂具有许多固有的化学性质，使钠离子电池（NIB）具有与众所周知的锂离子电池（LIB）相似的特性。 然而，除了其他差异之外，Na离子比Li离子大得多，因此Li离子存储的许多机制不适用于Na离子。 PI的初步结果表明，硬碳中钠储存的流行模型与系统的实验结果不一致。 随之而来的知识差距阻碍了下一代NIB的实现，因此PI致力于阐明硬碳中Na离子存储基本机制的新模型并测试该模型。 本研究的主要目的有三：（1）对硬碳的结构进行原子级的研究。(2)阐明钠离子插入硬碳的基础机制。(3)经验性地测试新模型预测硬碳的物理化学性质与NIB中相应的电化学行为之间的关系。 为了实现这些目标，研究人员团队汇集了硬碳的合成和电化学表征，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.