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Enhancing Interfacial Contact in Solid‐State Batteries with a Gradient Composite Solid Electrolyte
Author(s) -
Deng Chenglong,
Chen Nan,
Hou Chuanyu,
Liu Hanxiao,
Zhou Zhiming,
Chen Renjie
Publication year - 2021
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.202006578
Subject(s) - electrolyte , materials science , anode , composite number , chemical engineering , cathode , fast ion conductor , energy storage , battery (electricity) , polymer , electrode , contact resistance , solid solution , nanotechnology , composite material , chemistry , metallurgy , thermodynamics , engineering , power (physics) , physics , layer (electronics)
Solid‐state batteries promise to meet the challenges of high energy density and high safety for future energy storage. However, poor interfacial contact and complex manufacturing processes limit their practical applications. Herein, a simple strategy is proposed to enhance interfacial contact by introducing a gradient composite polymer solid electrolyte (GCPE), which is prepared by a facile UV‐curing polymerization technique. The high‐Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO)‐content side of the electrolyte exhibits high oxidation resistance (5.4 V versus Li + /Li), making it compatible with a high‐voltage cathode material, whereas the LLZTO‐deficient side achieves excellent interfacial contact with the Li metal anode, facilitating uniform Li deposition. Benefiting from the elaborate composition and structure of GCPE films, the symmetric Li//Li cell exhibits a low‐voltage hysteresis potential of 42 mV and a long cycle life of >1900 h without short‐circuiting. The Li//LiFePO 4 solid‐state batteries deliver a capacity of 161.0 mA h g −1 at 60 °C and 0.1 C (82.4% capacity is retained after 200 cycles). Even at 80 °C, the cell still shows an outstanding capacity of 132.9 mAh g −1 at 0.2 C after 100 cycles. The design principle of gradient electrolytes provides a new path for achieving enhanced interfacial contact in high‐performance solid‐state batteries.