First of all, Li-ion battery technology is not a single battery type rather it covers wide range of chemistries mostly variations on the cathode side while anode most of the time made up of carbon material i.e. graphite, and organic liquid based electrolytes.
Following are the names of major Lithium-ion battery chemistries. Their names indicates the chemistry of cathode material.
Lithium Cobalt Oxide(LiCoO2) — LCO
Lithium Iron Phosphate(LiFePO4) — LFP
Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) — NMC
Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2) — NCA
Lithium Manganese Oxide (LiMn2O4) — LMO
Lithium Titanate (Li2TiO3) — LTO
Why Lithium-Ion Battery dominating global battery market share?
Lithium-ion batteries, commercialized in 1991, are the fastest growing battery technologies and currently dominating rechargeable battery market in value and, thanks to its explosive growing at compound annual growth rate (CAGR) of >15%, it is expected to break-even with such a well-established and mature battery technology as lead-acid also in volume in the near future.
Well-established and mature battery technologies i.e. lead-acid, Nickel–cadmium and Nickel–metal hydride battery are losing market share to Lithium-ion batteries for following reasons:
Lithium-ion batteries have higher energy densities compared to other well-established and mature battery technologies i.e. lead-acid, Nickel–cadmium and Nickel–metal hydride batteries.
Lithium-ion batteries (100-265 Wh/kg or 250-670 Wh/L)
Lead-acid (35–40 Wh/kg)
Nickel–cadmium (40–60 Wh/kg)
Nickel–metal hydride battery (60–120 Wh/kg)
Lithium-ion batteries are more powerful compared to other well-established and mature battery technologies i.e. lead-acid, Nickel–cadmium and Nickel–metal hydride batteries.
Li-ion battery cells can deliver up to 3.6 Volts i.e. 3 times higher than technologies such as Ni-Cd or Ni-MH.
Declining Lithium-ion batteries prices.
Lithium-ion battery prices, which were above $1,100 per kilowatt-hour in 2010, have fallen 87% in real terms to $156/kWh in 2019, according to the latest forecast from research company BloombergNEF (BNEF) [1].
Other important characteristics of Lithium-ion batteries:
Long lifetime (i.e. as a rule of thumb Li-ion last for seven to twelve years).
Experiencing very low self-discharge rates (i.e. 1.5-2% per month).
Large choice of cell designs and battery chemistries.
Better cycling performances, typically thousands of charging/discharging cycles.
Highly scalable and it can be adapted to practically any voltage, power and energy requirement.
Difficulties and challenges for Lithium-ion batteries
Cost reductions
Lithium-ion battery prices, which were above $1,100 per kilowatt-hour in 2010, have fallen 87% in real terms to $156/kWh in 2019, according to the latest forecast from research company BloombergNEF (BNEF) [1]. Even though Lithium-ion batteries have seen tremendous price reductions but still we are not yet at the point where battery costs could allow renewables with storage to be competitive with a fossil fuel alternative for grid application or allow EVs to be at cost parity with an ICE engine across.
For grid scale applications, some researchers have estimated that energy storage would have to cost $10 to $20/kWh for a wind-solar mix with storage to be competitive with a nuclear power plant providing baseload electricity. And competing with a natural gas peaker plant would require energy storage costs to fall to $5/kWh [2]. Therefore, Lithium-ion battery has a long way to go before hitting that price tag.
Improvements in performance
Despite the Li-ion batteries have high energy density (100-265 Wh/kg or 250-670 Wh/L) compared to other kinds of batteries, Li-ion batteries are still around a hundred times less energy dense than gasoline (which contains 12,700 Wh/kg by mass or 8760 Wh/L by volume). Therefore, there is a need to have Li-ion batteries have with even higher gravimetric and volumetric energy densities, i.e. up to 700 Wh/kg and 1400 Wh/l, which is possible by using high capacity electrode materials (i.e. use of Li metal anode or SiO2 anode instead of graphite based anode) [3]. Improved gravimetric and volumetric energy densities would accelerate the wide scale adoption of Li-ion batteries for mobility and utility scale stationary storage applications.
PNNL is leading Battery500, a DOE-sponsored consortium that is developing higher energy lithium-metal batteries. The goal is to create a battery with a specific energy of 500 watt-hours per kilogram — about two-times more juice than today’s EV batteries [4].
Improvements in Safety
Even though modern Li-ion batteries boast superior energy density and power density compared to various well-established and mature battery technologies such as e.g. lead-acid, Ni-Cd, Ni-MH, etc. Li-ion batteries have some inherent safety issues mainly due to the use of highly flammable organic liquid electrolytes. Due to this reason, Li-ion batteries have a tendency to overheat and in some cases this can lead to thermal runaway and combustion (i.e. notably the grounding of the Boeing 787 fleet after onboard battery fires). These organic liquid electrolytes also limit the possibility of using high voltage electrode materials because electrolytes can be damaged at high voltages [3].
One solution is to use solid electrolytes but that means other compromises. It’s much harder to transfer anything from solids. Safer polymer or inorganic electrolytes could be a viable alternative to the high flammable organic liquid electrolytes currently used in Li-ion batteries.
Recyclability of Li-ion batteries
Industry analysts predict that by 2020, China alone will generate some 500,000 metric tons of used Lithium-ion batteries and that by 2030, the worldwide number will hit 2 million metric tons per year [5]. If current trends for handling these spent batteries hold, most of those batteries may end up in landfills even though Li-ion batteries can be recycled. These popular power packs contain valuable metals and other materials that can be recovered, processed, and reused. But very little recycling goes on today. In Australia, for example, only 2–3% of Li-ion batteries are collected and sent offshore for recycling, according to Naomi J. Boxall, an environmental scientist at Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO). The recycling rates in the European Union and the US—less than 5%—aren’t much higher.
Definitely, there are many reasons and challenges why Li-ion battery recycling is not yet a universally well-established practice that includes technical constraints, economic barriers, logistic issues, and regulatory gaps. But opportunities always coexist with challenges.
Other challenges for Li-ion batteries
Finding alternatives to scarce electrode materials to improve energy density and decrease the impact on the environment and society.
Implement self-healing mechanisms to improve battery life.
Develop more efficient manufacturing lines to decrease cost.
Convergence of synthesis, advance characterization, human insight and scientific machine learning technologies to accelerate the battery development process.
Conclusion
Lithium-ion batteries are anticipated to have a high rate of deployment in the coming decades. Ideal applications of Lithium-ion batteries would be energy storage systems for renewables and transportation. The downside of Lithium-ion batteries is that Lithium-ion batteries have significant associated adverse impacts, including human rights and pollution impacts during mining, fire risk, and are a future waste management challenge owing to the lack of established recycling systems. Therefore, planning and decision-making influencing the deployment of current and future Lithium-ion battery technologies need to acknowledge and manage these short and longer-term impacts as they pose a significant risk to the viability of the industry and could hinder the transition to a renewable energy system.
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