摘要
Biomass-derived hard carbons,usually prepared by pyrolysis,are widely considered the most promising anode materials for sodium-ion bat-teries(SIBs)due to their high capacity,low poten-tial,sustainability,cost-effectiveness,and environ-mental friendliness.The pyrolysis method affects the microstructure of the material,and ultimately its so-dium storage performance.Our previous work has shown that pyrolysis in a sealed graphite vessel im-proved the sodium storage performance of the car-bon,however the changes in its microstructure and the way this influences the sodium storage are still unclear.A series of hard carbon materials derived from corncobs(CCG-T,where T is the pyrolysis temperature)were pyrolyzed in a sealed graphite vessel at different temperatures.As the pyrolysis temperature increased from 1000 to 1400℃ small carbon domains gradually transformed into long and curved domains.At the same time,a greater number of large open pores with uniform apertures,as well as more closed pores,were formed.With the further increase of pyrolysis temperature to 1600℃,the long and curved domains became longer and straighter,and some closed pores gradually became open.CCG-1400,with abundant closed pores,had a superior SIB performance,with an initial reversible ca-pacity of 320.73 mAh g^(-1) at a current density of 30 mA g^(-1),an initial Coulomb efficiency(ICE)of 84.34%,and a capacity re-tention of 96.70%after 100 cycles.This study provides a method for the precise regulation of the microcrystalline and pore structures of hard carbon materials.
生物质硬炭因其高容量、低电位、可持续性、成本效益和环境友好性,被广泛认为是最有前途的钠离子电池负极材料。生物质硬炭材料通常通过热解方法制备,但热解方式会影响材料的微观结构,并最终影响硬炭材料的储钠性能。前期研究已证明在密闭石墨罐中热解能有效地提升硬炭材料的储钠性能,然而其微观结构的演变规律及其对材料储钠性能的影响机制尚不清楚。因此本文采用密闭石墨罐辅助热解技术在不同热解温度下制备了系列玉米芯基硬炭材料(CCG-T,T为热解温度)。随着热解温度从1000℃升高到1400℃,小碳畴逐渐转变为长而弯曲的碳畴。同时,形成了更多的孔径均匀的大开孔和更多的闭孔。随着热解温度进一步升高至1600℃,长而弯曲的碳畴变长变直,部分闭孔逐渐变为开孔。其中CCG-1400具有优异的储钠性能,在电流密度为30 mAg^(-1)时,初始可逆容量为320.73 mAhg^(-1),初始库仑效率(ICE)为84.34%,循环100次后容量保持率为96.70%。本研究为精确调控硬碳材料的微晶结构和孔隙结构提供了一种方法。
出处
《新型炭材料(中英文)》
北大核心
2025年第2期377-391,共15页
New Carbon Materials
基金
山西省基础研究计划(202203021222291)
山西省科技创新人才团队(202204051001005)
山西省重点研发计划(202202040201007)
山西省基础研究计划(202403021221003).
作者简介
第一作者:宋宁静,副教授.E-mail:snj@jzxy.edu.cn;通讯作者:马灿良,副教授.E-mail:macanliang@sxu.edu.cn。
