In-situ total Li depth profiling of solid state Li ion batteries under charging and discharging by means of transmission elastic recoil detection analysis with 5 MeV He~(2+) ions

摘要

Total Li depth profiles in Ti/NbO/LiPON/LMO batteries prepared on self-supporting Al and Ti substrates have been measured under charging and discharging by means of TERD and RBS techniques. Since TERD spectrum for as-received specimen of Ti/NbO/LiPON/LMO/Al showed that Li diffused from LMO to NbO during its preparation, at first, the discharging was performed by biasing at -0.5 V. Hereafter, the charging was performed at 3.2 V. TERD spectra under discharging clearly showed that Li in NbO was reduced and that in LMO and Al near LMO was enriched and more over Li in UPON was reduced near NbO, while that was enriched near LMO. TERD spectra under charging also clearly showed 'vice versa' that Li in LMO and Al near LMO was reduced and that in NbO was enriched. Ti/NbO/LiPON/LMO/Ti was also charged and hereafter discharged. It was found that this battery was also rechargeable at one cycle.