Solid-state batteries: from fundamental interface characterization to realize sustainable promise
来源期刊：Rare Metals2020年第7期
论文作者：Yu-Xin Gong Jia-Jun Wang
文章页码：743 - 744
摘 要：<正>The highly conductive solid-state electrolytes （SSEs） have led to great progress in the development of all-solid-state batteries （ASSBs）; however, there are obstacles to their application such as poor interfacial stability, scalability challenges, production safety and sustainability of ASSBs which still demand prompt solution. In Nature Nanotechnology, Tan and colleagues summarize solutions to overcome some major fundamental obstacles faced by the ASSB community, as well as potential strategies toward a
Solid-state batteries: from fundamental interface characterization to realize sustainable promise
Yu-Xin Gong Jia-Jun Wang
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology
作者简介：*Jia-Jun Wang e-mail: jiajunhit@hit.edu.cn;
Solid-state batteries: from fundamental interface characterization to realize sustainable promise
Yu-Xin Gong Jia-Jun Wang
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology
The highly conductive solid-state electrolytes(SSEs)have led to great progress in the development of all-solid-state batteries(ASSBs);however,there are obstacles to their application such as poor interfacial stability,scalability challenges,production safety and sustainability of ASSBs which still demand prompt solution.In Nature Nanotechnology,Tan and colleagues summarize solutions to overcome some major fundamental obstacles faced by the ASSB community,as well as potential strategies toward a sustainable ASSB recycling model
[
1]
.
As for solid-state electrolyte chemistry,Tan mainly discussed the instability behaviors of ASSBs,which arises from(1)interfacial reactions between the electrode and SSE and(2)electrochemical decomposition of the SSE during cell cycling at high voltages,and evaluate the modification strategies to inhibit those solid-state battery interfacial reactions.Protective coating on the cathodes can effectively prevent the interfacial reaction between cathode and SSE while the reactions between anode and SSE can be effectively inhibited with the usage of interphase layers such as lithium phosphorous oxynitride(LiPON)
[
2,
3]
.In addition,in order to reduce the electrochemical decomposition of SSE,their thermodynamics can be altered through chemical compositional changes.
Characterization of ASSBs with conventional tools can be a challenge with difficulties to probe buried and beam sensitive interfaces,which means it is even knottier to process in situ experiments in the meantime.X-ray computed tomography(CT)has been used to provide nondestructive three-dimensional(3D)in situ spatial visualization(Fig.1a)of dynamic morphological changes at solid–solid anodic interfaces
[
4]
;however,its application is limited with poor X-ray absorption of lithium.Compared to X-ray CT,neutron depth profiling(NDP)is effective to study lithium dendritic growth,as it is nondestructive and lithium-sensitive.Cryogenic focused ion beam(FIB)techniques can help quantify porosity and volume changes within the ASSBs at spatial resolutions under 1 nm without damaging the SSE(Fig.1b)
[
5]
.Besides,using in situ spectroscopy can provide valuable information in solidstate batteries due to the strong scattering signals(Raman)or surface chemistry(XPS)information of covalently bonded interfacial products of active materials(Fig.1c,d)
[
6,
7]
.
In order to achieve practical energy densities and qualified mechanical properties which is critical to the stable manufacture of large-scale electrolytes,polymer composites are introduced as solvents and binders.However,the mixture of binder and SSEs can lead to the decrease in its conductivity due to the impedance contribution across the polymer–SSE interface.A heat-treated method
[
8]
which allows for the removal of volatile poly(propylene carbonate)-based binder within the cell after fabrication is introduced.When done under stack pressure,it allows the thermally softened SSEs to deform and fill any pores generated within the solid electrolyte bulk.
Unlike the conventional lithium ion batteries which were designed without much attention on eco-friendly recycling,researchers need pay more attention on designing reusability and recyclability for ASSBs.According to the core principles of battery recycling raised by the US Department of Energy’s ReCell Center,this review presents an opportunity to explore possible pathways for recycling ASSBs using the goals of ReCell as a starting reference point.By using polar solvents such as ethanol or acetonitrile to recover certain kinds of sulfide-based SSEs from spent ASSBs,the SSE can be dissolved without chemical degradation
[
9]
.
Fig.1 a Nano-computed tomography showing 3D elemental map within solid electrolytes
[1](Copyright 2020,Springer Nature).b cryogenic FIB-based reconstruction enable quantification of 3D volume and porosity at nano-resolution
[5](Copyright 2019,American Chemical Society).c in situ Raman spectroscopy tracking exchange of lithium species units during plating and stripping
[7](Copyright 2017,American ChemicalSociety).d in situ XPS offering surface chemistry of solid-state electrolytes
[6](Copyright 2013,American Chemical Society)
Overall,this review by Tan and colleagues provides a realistic assessment of the current state-of-the-art characterization techniques and evaluate future full cell ASSB prototyping strategies.It presents an important and comprehensive reference to ASSB researchers.
