Sundaram Manickam Minakshi, Appadoo Dominique
College of Science, Health, Engineering & Education, Murdoch University, WA 6150, Australia.
THz-Far Infrared Beamline, ANSTO-Australian Synchrotron, Clayton, Victoria 3168, Australia.
Dalton Trans. 2020 Aug 25;49(33):11743-11755. doi: 10.1039/d0dt01871f.
The electrochemical energy storage of lithium and sodium ions from aqueous solutions in binary metal oxides is of great interest for renewable energy storage applications. Binary metal oxides are of interest for aqueous energy storage due to their better structural stability and electronic conductivity and tunability of redox potentials. They have also been widely studied as novel electrodes for supercapacitors. The interactions between water and lithium/sodium ions, and water and binary metal oxide surface determine the electrochemical reactions and their long-term stability. Our results indicate that the aqueous sodium electrolyte has a stronger influence on the capacitance and cycling stability of the binary (Ca and Mo) metal oxide electrode than its lithium cousin. The symmetric cell in a two-electrode configuration was assembled with the proposed binary metal oxide, which shows an average discharge voltage of 1.2 V, delivering a specific capacitance of 72 F g-1 at a specific energy density of 32 W h kg-1 based on the total mass of the active materials. The development of highly concentrated aqueous electrolytes such as the "water-in-salt" electrolyte showed a larger electrochemical (voltage) window with enhanced storage capacitance for increasing the salt concentrations has also been discussed.
二元金属氧化物中来自水溶液的锂和钠离子的电化学储能在可再生能源存储应用中备受关注。二元金属氧化物因其更好的结构稳定性、电子导电性和氧化还原电位的可调性而在水系储能方面具有吸引力。它们也作为超级电容器的新型电极得到了广泛研究。水与锂/钠离子之间以及水与二元金属氧化物表面之间的相互作用决定了电化学反应及其长期稳定性。我们的结果表明，与锂基电解质相比，水系钠电解质对二元（钙和钼）金属氧化物电极的电容和循环稳定性有更强的影响。采用所提出的二元金属氧化物组装了两电极配置的对称电池，基于活性材料的总质量，该电池在特定能量密度为32 W h kg-1时显示出1.2 V的平均放电电压，比电容为72 F g-1。还讨论了诸如“盐包水”电解质等高浓度水系电解质的发展，其具有更大的电化学（电压）窗口，随着盐浓度增加存储电容增强。
