Affiliation:
1. State Key Laboratory of Pulp and Paper Engineering South China University of Technology Guangzhou 510641 China
2. Department of Chemistry UBC Faculty of Science, Vancouver Campus 2036 Main Mall Vancouver BC Canada V6T 1Z1
3. Department of Mechanical Engineering National University of Singapore 3 Engineering Drive 2 Singapore 117576 Singapore
Abstract
The separator is an essential component of sodium‐ion batteries (SIBs) to determine their electrochemical performances. However, the separator with high mechanical strength, good electrolyte wettability and excellent electrochemical performance remains an open challenge. Herein, a new separator consisting of amphoteric nanofibers with abundant functional groups was fabricated through supramolecular assembly of natural polymers for SIB. The uniform nanoporous structure, remarkable mechanical properties and abundant functional groups (e.g. −COOH, −NH2 and −OH) endow the separator with lower dissolution activation energy and higher ion migration numbers. These metrics enable the separator to lower the barrier for desolvation of Na+, accelerate the migration of Na+, and generate more stable solid electrolyte interphase (SEI) and cathode electrolyte interphase (CEI). The battery assembled with the amphoteric nanofiber separator shows higher specific capacity and better stability than that assembled with glass fiber (GF) separator.
Funder
Basic and Applied Basic Research Foundation of Guangdong Province