The toxicity analysis of combustion products from commercialized Li-ion batteries was performed in this work. More than 100 emitted gaseous products are identified, most of which are hazardous to the human beings and trigger negative impact on the environment. Moreover, the states of charge of battery was found to significantly affect the types of toxic combustion products, and the 100% state of charge even led to the most serious toxicity. The relationship between the concentration of toxic combustion products and battery capacity was also investigated. Interestingly, the concentration of carbon monoxide rose up rapidly up on the increase of the capacity instead of the toxic organic products. This investigation suggests that the efforts on effective battery emergency response could be potentially simplified to achieve cost down for manufacturers.