Abstract:
Lithium/sulfur (Li/S) battery is a promising candidate for the next generation rechargeable battery
since the negative electrode, lithium, and the cathode, sulfur, have the highest theoretical capacities
of 3862 and of 1672 mAh/g, respectively, among any other active materials, e.g., graphite (372
mAh/g) or LiCoO2 (274 mAh/g, only about 50% is practically available). However, there are several
challenging issues in order to realize the use of this type of next generation battery. First, the
lithium metal anode has an intrinsic safety issue, dendrite growth that can result in internal short
circuit failure. Second, the sulfur cathode is a very insulating material; therefore, sulfur-based
cathodes need a large amount of conducting additives, resulting in the decrease in the practically
available gravimetric capacity per the unit mass of cathode composite. Third, lithium polysulfides,
reduced (discharged) forms of sulfur, dissolve into an electrolyte solution, resulting in capacity
fading. For realistic battery applications, these issues from both the anode and the cathode need to
be solved or mitigated. To this end, we integrate three practically possible solutions: (1)
manufacture-friendly pre-lithiation of anode or cathode materials, (2) practically optimal choice of
conducting agent and of the method for S/conductive-agent integration, and (3) stabilization of
discharged forms of the cathode.