Abstract
Na3V2(PO4)2F3 (NVPF) has been considered an up-and-coming cathode material candidate for sodium (Na) ion batteries in light of its high specific capacity and working voltage. However, an erratic cathode/electrolyte interface layer is inevitably formed, accompanied by continuous electrolyte decomposition on the NVPF surface, when the voltage exceeds 4.2 V vs Na+/Na. Herein, the interphase features of NVPF are obviously enhanced owing to the ameliorated electronic conductivity obtained by combining it with carbon nanotubes (CNT). The NVPF with 3 wt % CNT (NVPF@3% CNT) reduces the Na+ diffusion kinetic energy barrier and electron transport resistance. Furthermore, the conducting network formed by CNT with sturdy structure strength can promptly accommodate the volumetric changes during sequential Na+ extraction/insertion and thus effectively improve the long-term cyclic performance of NVPF/hard carbon full cells. The initial discharge capacity approaches 105 mA h g-1 at 0.5C, and it retains 94% capacity retention after 200 cycles at the temperature of −10 °C. The cathode/electrolyte interphase characterization results further demonstrate that the interphase layer on the NVPF@3% CNT cathode is thinner and more compact compared with pristine samples. This research provides a competitive strategy to facilitate the interfacial compatibility between the NVPF and electrolytes and accelerate the commercialization of high-performance Na-ion batteries.
Original language | English |
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Pages (from-to) | 12992-13001 |
Number of pages | 10 |
Journal | ACS Sustainable Chemistry and Engineering |
Volume | 11 |
Issue number | 35 |
DOIs | |
State | Published - Sep 4 2023 |
Funding
This work was financially supported by the National Natural Science Foundation of China (No. 52202228), and funded by Science Research Project of Hebei Education Department (No. BJK2022011) and Central Funds Guiding the Local Science and Technology Development of Hebei Province (No. 236Z4404G). X.S. and S.D. were supported by the U.S. Department of Energy’s Office of Science, Office of Basic Energy Science, Materials Sciences and Engineering Division.
Funders | Funder number |
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Central Funds Guiding the Local Science and Technology Development of Hebei Province | 236Z4404G |
U.S. Department of Energy | |
Office of Science | |
Basic Energy Sciences | |
Division of Materials Sciences and Engineering | |
National Natural Science Foundation of China | 52202228 |
Department of Education of Hebei Province | BJK2022011 |
Keywords
- NaV(PO)F cathode
- carbon nanotubes
- cathode/electrolyte interphase
- electronic conductivity
- sodium-ion batteries