Lahiru Sandaruwan Ranehipura Dewage, Kuramoto Ryuji, Wang Boyu, Ma Shunchao, Wang Hongyu
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China.
School of Applied Chemistry and Engineering, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, P. R. China.
Langmuir. 2022 Jul 26;38(29):8934-8942. doi: 10.1021/acs.langmuir.2c01115. Epub 2022 Jul 15.
Nowadays, poly(vinylidene fluoride) (PVdF) has been dominantly utilized as a polymeric binder in commercialized Li-ion batteries. However, standardized PVdF-based electrode manufacturing seems cost-intensive and environmentally hazardous, which relies on the usage of toxic -methyl-2-pyrrolidone (NMP) as a dispersant. In view of cost control and environmental awareness, switching to a water-processable green binder, as a substitute for PVdF, has been imperative with realistic significance. Herein, commercially available white latex (WL), containing poly(vinyl acetate) as a staple ingredient, was directly used as an alternative aqueous binder for PVdF in the fabrication of graphite/LiTiO-based lithium-ion anodes. WL exhibits robust adhesion of the electrode coating to the current collector; meanwhile, the restricted electrolyte swelling of the binder is verified by in situ electrochemical dilatometry. Outperforming PVdF, WL endows graphite with extensive surface coverage by the binding agent, dramatically reducing irreversible decomposition of the electrolyte (SEI formation) on graphite. Consequently, the WL-based graphite anode delivers the highest initial coulombic efficiency (CE) of 92% and remarkable long cyclic stability with a high capacity retention of 332.7 mAh/g, compared to the PVdF- and carboxymethyl cellulose (CMC)-based ones. Moreover, WL is also compatible with LiTiO, endowing it with more stable cycling behavior than that of the counterparts prepared with both PVdF and even CMC. Our described WL represents an appealing "green" alternative for PVdF in manufacturing sustainable and ecofriendly energy storage devices.
如今,聚偏氟乙烯(PVdF)在商业化锂离子电池中一直被主要用作聚合物粘结剂。然而,基于PVdF的标准化电极制造似乎成本高昂且对环境有害,这依赖于使用有毒的N-甲基-2-吡咯烷酮(NMP)作为分散剂。鉴于成本控制和环保意识,转而使用可水加工的绿色粘结剂来替代PVdF已成为具有现实意义的当务之急。在此,含有聚醋酸乙烯酯作为主要成分的市售白色乳胶(WL)被直接用作PVdF的替代水性粘结剂,用于制备石墨/LiTiO基锂离子负极。WL表现出电极涂层对集流体的强附着力;同时,通过原位电化学膨胀法验证了粘结剂有限的电解质溶胀。与PVdF相比,WL使粘结剂对石墨具有广泛的表面覆盖,显著减少了石墨上电解质的不可逆分解(固体电解质界面膜形成)。因此,与基于PVdF和羧甲基纤维素(CMC)的石墨负极相比,基于WL的石墨负极具有92%的最高初始库仑效率(CE)以及显著的长循环稳定性,高容量保持率为332.7 mAh/g。此外,WL也与LiTiO兼容,使其循环行为比用PVdF甚至CMC制备的同类产品更稳定。我们所描述的WL在制造可持续和环保的储能装置方面是PVdF一种有吸引力的“绿色”替代品。