Lithium ion batteries made of electrodes with 99 wt% active materials and 1 wt% carbon nanotubes without binder or metal foils

作者：Hasegawa Kei; Noda Suguru^*

来源：Journal of Power Sources, 2016, 321: 155-162.

DOI：10.1016/j.jpowsour.2016.04.130

• Lithium ion battery
• Carbon nanotube
• Binder free
• Three-dimensional current collector
• Laminate cell

Herein, we propose lithium ion batteries (LIBs) without binder or metal foils, based on a three-dimensional carbon nanotube (CNT) current collector. Because metal foils occupy 20-30 wt% of conventional LIBs and the polymer binder has no electrical conductivity, replacing such non-capacitive materials is a valid approach for improving the energy and power density of LIBs. Adding only 1 wt% of few-wall CNTs to the active material enables flexible freestanding sheets to be fabricated by simple dispersion and filtration processes. Coin cell tests are conducted on full cells fabricated from a 99 wt% LiCoO2-1 wt% CNT cathode and 99 wt% graphite-1 wt% CNT anode. Discharge capacities of 353 and 306 mAh g(graphite)(-1) are obtained at charge-discharge rates of 37.2 and 372 mA g(graphite)(-1) respectively, with a capacity retention of 65% at the 500th cycle. The suitability of the 1 wt% CNT-based composite electrodes for practical scale devices is demonstrated with laminate cells containing 50 x 50 mm(2) electrodes. Use of metal combs instead of metal foils enables charge-discharge operation of the laminate cell without considerable IR drop. Such electrodes will minimize the amount of metal and maximize the amount of active materials contained in LIBs.

• 出版日期2016-7-30