Manufacturing & Regional Cost Competitiveness of Commercial Sodium Ion Cells : A bottom-up cost analysis of Lithium and Sodium Ion Battery Storage

Abstract: Batteries are increasingly seen as an indispensable element in the rapid progress of the energy transition. With forecasts for global demand set to reach 2 TWh by 2030 and increasing policy support for battery manufacturers, many questions arise on whether the current rapid expansion of battery manufacturing industry is sustainable. Issues regarding the stability of the supply chain and rising energy security concerns has led to an expanded focus on alternate battery technologies. Sodium ion cells are commonly cited as a potential solution to many of the current issues facing the lithium-ion battery industry. With sodium ion cells reaching commercialization, this thesis would like to explore the viability of commercial sodium ion cells through a bottom-up manufacturing and regional cost analysis of Sodium Prussian Blue Analogues and Sodium Layered Oxides. To account for the more qualitative aspects of regional battery manufacturing, the current policy framework and supply chain are briefly explored. To study the current commercial sodium ion cells, the report considers Na0.9[Cu0.22Fe0.30Mn0.48] O2 (Na Oxide) and Na2MnFe(CN)6 (Na PBA) cathode chemistries which are similar to the cells manufactured by HiNa and Novasis Energies respectively. These cells are compared to two of the most common Lithium chemistries on the market, LiFePO4 (LFP) and LiNi0.3Mn0.3Co0.3 (Li NMC111). Various manufacturing scales of the model plant are explored for each chemistry, and the changes in manufacturing costs for the US, China, India, Sweden and Chile are explored. Considering a baseline plant of 1500 MWh/yr, the base case results show that from the cost perspective the sodium ion cells are not too different from that of the lithium-ion cells. The cost of the lithium ion cells NMC111 and LFP (2019 US$) are at 126 $/kWh and 113$/kWh while the Na Oxide and Na PBA cell costs are at 125 $/kWh and 148 $/kWh. While the costs are comparable, the volumetric energy density of the sodium cells is almost half that of their lithium counterparts, which hampers the overall cost advantage from the cheaper materials. Compared to the lithium cells where the cathode and anode are on average the most expensive components, the separator and the hard carbon anode become the most expensive cost components in the sodium ion cells studied. In the regional analysis, China and Chile have the cheapest cell costs for both sodium and lithium, while the US and India are the most expensive within the countries studied with the maximum cost difference in the range of 15 $/kWh. While most countries have differing approaches in terms of policy support, the trend towards domestic sourcing of supplies can clearly be seen in most of the countries studied. The past three years has seen interest in battery manufacturing escalate significantly, with slow policy support in the 2010s from most countries. Chile is a notable exception with a lack of strong policy support. For the manufacturing scale, it was found that the minimum effective scale was 1500 MWh annually. The capital costs for the sodium ion cell plants were 16% more expensive than the lithium cell plants due to increased production rates to meet the same annual production. With cathode thickness, it was found that the Na PBA cell benefited the most with the increase in thickness, as it had the highest CAM capacity. The cost advantages of the sodium ion cells start to materialise when considering the increase in price of materials in 2022. When considering increased metal costs in 2022, the price of the Li NMC and LFP cells increase to around 186 $/kWh, while sodium ion cells don’t display an appreciable change in cost. Furthermore, when considering a higher power rate of 5C, the lithium cells perform poorly with Li NMC increasing to 188 $/kWh and LFP to 148 $/kWh while the sodium cells remain close to their 0.2C costs at 148$/kWh for Na PBA and 127 $/kWh for Na Oxide.