The inevitable shift to electric vehicles (EVs), the rapid growth of drone market, and the increasing share of electricity generation from renewable sources strongly depend on secondary batteries. The market requires for batteries to have higher volumetric and gravimetric energy densities, making the product smaller and lighter. While maintaining the high energy density, it should be safe during its operation avoiding catastrophic thermal runaway. The shorter charging time and lower cost are also essential to win the battle in the EV and drone markets. Significant efforts from academia, national labs, and industries have been devoted to resolve these issues, however, more fundamental as well as collaborative researches are necessary to meet the demand from the markets.